diff --git a/README.md b/README.md
index a2ea519a1..40f5cafe4 100644
--- a/README.md
+++ b/README.md
@@ -19,21 +19,21 @@ USAGE:
    gopm [global options] command [command options] [arguments...]
 
 VERSION:
-   0.6.0.1209
+   0.6.1.0110
 
 COMMANDS:
-   get		fetch remote package(s) and dependencies to local repository
-   bin		download and link dependencies and build executable binary
-   gen		generate a gopmfile according current Go project
-   run		link dependencies and go run
-   build	link dependencies and go build
-   install	link dependencies and go install
-   help, h	Shows a list of commands or help for one command
+   get      fetch remote package(s) and dependencies to local repository
+   bin      download and link dependencies and build executable binary
+   gen      generate a gopmfile according current Go project
+   run      link dependencies and go run
+   build link dependencies and go build
+   install  link dependencies and go install
+   help, h  Shows a list of commands or help for one command
 
 GLOBAL OPTIONS:
-   --noterm		disable color output
-   --version, -v	print the version
-   --help, -h		show help
+   --noterm    disable color output
+   --version, -v  print the version
+   --help, -h     show help
 ```
 
 
diff --git a/cmd/build.go b/cmd/build.go
index 4e4feaf21..5461e586d 100644
--- a/cmd/build.go
+++ b/cmd/build.go
@@ -34,6 +34,7 @@ and execute 'go build'
 gopm build <go build commands>`,
 	Action: runBuild,
 	Flags: []cli.Flag{
+		cli.BoolFlag{"update, u", "update pakcage(s) and dependencies if any"},
 		cli.BoolFlag{"verbose, v", "show process details"},
 	},
 }
diff --git a/cmd/cmd.go b/cmd/cmd.go
index d2bff0c43..8a2d5d24a 100644
--- a/cmd/cmd.go
+++ b/cmd/cmd.go
@@ -1,4 +1,4 @@
-// Copyright 2013 gopm authors.
+// Copyright 2013-2014 gopm authors.
 //
 // Licensed under the Apache License, Version 2.0 (the "License"): you may
 // not use this file except in compliance with the License. You may obtain
@@ -57,24 +57,22 @@ func validPath(info string) (string, string) {
 	l := len(infos)
 	switch {
 	case l == 1:
-		// for local imports
+		// For local imports.
 		if com.IsFile(infos[0]) {
 			return doc.LOCAL, infos[0]
 		}
-
-		return doc.BRANCH, ""
 	case l == 2:
 		switch infos[1] {
 		case doc.TRUNK, doc.MASTER, doc.DEFAULT:
 			infos[1] = ""
 		}
 		return infos[0], infos[1]
-	default:
-		log.Error("", "Cannot parse dependency version:")
-		log.Error("", "\t"+info)
-		log.Help("Try 'gopm help get' to get more information")
-		return "", ""
 	}
+
+	log.Error("", "Cannot parse dependency version:")
+	log.Error("", "\t"+info)
+	log.Help("Try 'gopm help get' to get more information")
+	return "", ""
 }
 
 func versionSuffix(value string) string {
@@ -83,3 +81,7 @@ func versionSuffix(value string) string {
 	}
 	return ""
 }
+
+func isSubpackage(rootPath, targetPath string) bool {
+	return strings.HasSuffix(workDir, rootPath) || strings.HasPrefix(rootPath, targetPath)
+}
diff --git a/cmd/gen.go b/cmd/gen.go
index 7cdf0f283..6abd821d8 100644
--- a/cmd/gen.go
+++ b/cmd/gen.go
@@ -41,7 +41,6 @@ Make sure you run this command in the root path of a go project.`,
 	},
 }
 
-// scan a directory and gen a gopm file
 func runGen(ctx *cli.Context) {
 	setup(ctx)
 
@@ -55,15 +54,18 @@ func runGen(ctx *cli.Context) {
 		log.Fatal("", "\t"+err.Error())
 	}
 
+	targetPath := parseTarget(gf.MustValue("target", "path"))
 	// Get dependencies.
-	imports := doc.GetAllImports([]string{workDir},
-		parseTarget(gf.MustValue("target", "path")), ctx.Bool("example"))
+	imports := doc.GetAllImports([]string{workDir}, targetPath, ctx.Bool("example"))
 
 	for _, p := range imports {
 		p = doc.GetProjectPath(p)
-		if strings.HasSuffix(workDir, p) {
+		// Skip subpackage(s) of current project.
+		if strings.HasSuffix(workDir, p) || strings.HasPrefix(p, targetPath) {
 			continue
 		}
+
+		// Check if user specified the version.
 		if value := gf.MustValue("deps", p); len(value) == 0 {
 			gf.SetValue("deps", p, "")
 		}
diff --git a/cmd/get.go b/cmd/get.go
index ec0e81fb4..6a90b1aca 100644
--- a/cmd/get.go
+++ b/cmd/get.go
@@ -1,4 +1,4 @@
-// Copyright 2013 gopm authors.
+// Copyright 2013-2014 gopm authors.
 //
 // Licensed under the Apache License, Version 2.0 (the "License"): you may
 // not use this file except in compliance with the License. You may obtain
@@ -69,7 +69,6 @@ func init() {
 
 func runGet(ctx *cli.Context) {
 	setup(ctx)
-
 	// Check conflicts.
 	if ctx.Bool("gopath") && ctx.Bool("remote") {
 		log.Error("get", "Command options have conflicts")
@@ -100,7 +99,7 @@ func runGet(ctx *cli.Context) {
 	}
 
 	// The gopm local repository.
-	installRepoPath = doc.HomeDir + "/repos"
+	installRepoPath = path.Join(doc.HomeDir, "repos")
 	log.Log("Local repository path: %s", installRepoPath)
 
 	// Check number of arguments to decide which function to call.
@@ -119,11 +118,17 @@ func getByGopmfile(ctx *cli.Context) {
 	}
 	gf := doc.NewGopmfile(".")
 
+	targetPath := parseTarget(gf.MustValue("target", "path"))
 	// Get dependencies.
-	imports := doc.GetAllImports([]string{workDir},
-		parseTarget(gf.MustValue("target", "path")), ctx.Bool("example"))
+	imports := doc.GetAllImports([]string{workDir}, targetPath, ctx.Bool("example"))
+
 	nodes := make([]*doc.Node, 0, len(imports))
 	for _, p := range imports {
+		p = doc.GetProjectPath(p)
+		// Skip subpackage(s) of current project.
+		if isSubpackage(p, targetPath) {
+			continue
+		}
 		node := doc.NewNode(p, p, doc.BRANCH, "", true)
 
 		// Check if user specified the version.
@@ -166,12 +171,20 @@ func getByPath(ctx *cli.Context) {
 }
 
 func copyToGopath(srcPath, destPath string) {
+	importPath := strings.TrimPrefix(destPath, installGopath+"/")
+	if len(getVcsName(destPath)) > 0 {
+		log.Warn("Package in GOPATH has version control: %s", importPath)
+		return
+	}
+
 	os.RemoveAll(destPath)
 	err := com.CopyDir(srcPath, destPath)
 	if err != nil {
 		log.Error("download", "Fail to copy to GOPATH:")
 		log.Fatal("", "\t"+err.Error())
 	}
+
+	log.Log("Package copied to GOPATH: %s", importPath)
 }
 
 // downloadPackages downloads packages with certain commit,
@@ -184,91 +197,103 @@ func downloadPackages(ctx *cli.Context, nodes []*doc.Node) {
 		if n.Type == doc.LOCAL {
 			continue
 		}
-		// Check if it is a valid remote path.
-		if doc.IsValidRemotePath(n.ImportPath) {
-			gopathDir := path.Join(installGopath, n.ImportPath)
-			n.RootPath = doc.GetProjectPath(n.ImportPath)
-			installPath := path.Join(installRepoPath, n.RootPath) +
-				versionSuffix(n.Value)
-
-			if !ctx.Bool("update") {
-				// Check if package has been downloaded.
-				if (len(n.Value) == 0 && !ctx.Bool("remote") && com.IsExist(gopathDir)) ||
-					com.IsExist(installPath) {
-					log.Trace("Skipped installed package: %s@%s:%s",
-						n.ImportPath, n.Type, doc.CheckNodeValue(n.Value))
-
-					if ctx.Bool("gopath") && com.IsExist(installPath) {
-						copyToGopath(installPath, gopathDir)
-						log.Log("Package copied to GOPATH: %s", n.ImportPath)
-					}
-					continue
-				} else {
-					doc.LocalNodes.SetValue(n.RootPath, "value", "")
+		// Check if it is a valid remote path or C.
+		if n.ImportPath == "C" {
+			continue
+		} else if !doc.IsValidRemotePath(n.ImportPath) {
+			// Invalid import path.
+			log.Error("download", "Skipped invalid package: "+fmt.Sprintf("%s@%s:%s",
+				n.ImportPath, n.Type, doc.CheckNodeValue(n.Value)))
+			failConut++
+			continue
+		}
+
+		// Valid import path.
+		gopathDir := path.Join(installGopath, n.ImportPath)
+		n.RootPath = doc.GetProjectPath(n.ImportPath)
+		installPath := path.Join(installRepoPath, n.RootPath) + versionSuffix(n.Value)
+
+		if isSubpackage(n.RootPath, ".") {
+			continue
+		}
+
+		// Indicates whether need to download package again.
+		if n.IsFixed() && com.IsExist(installPath) {
+			n.IsGetDepsOnly = true
+		}
+
+		if !ctx.Bool("update") {
+			// Check if package has been downloaded.
+			if (len(n.Value) == 0 && !ctx.Bool("remote") && com.IsExist(gopathDir)) ||
+				com.IsExist(installPath) {
+				log.Trace("Skipped installed package: %s@%s:%s",
+					n.ImportPath, n.Type, doc.CheckNodeValue(n.Value))
+
+				// Only copy when no version control.
+				if ctx.Bool("gopath") && com.IsExist(installPath) ||
+					len(getVcsName(gopathDir)) == 0 {
+					copyToGopath(installPath, gopathDir)
 				}
+				continue
+			} else {
+				doc.LocalNodes.SetValue(n.RootPath, "value", "")
 			}
+		}
 
-			if !downloadCache[n.RootPath] {
-				// Download package.
-				nod, imports := downloadPackage(ctx, n)
-				if len(imports) > 0 {
-					var gf *goconfig.ConfigFile
-
-					// Check if has gopmfile
-					if com.IsFile(installPath + "/" + doc.GOPM_FILE_NAME) {
-						log.Log("Found gopmfile: %s@%s:%s",
-							n.ImportPath, n.Type, doc.CheckNodeValue(n.Value))
-
-						gf = doc.NewGopmfile(installPath)
-					}
-
-					// Need to download dependencies.
-					// Generate temporary nodes.
-					nodes := make([]*doc.Node, len(imports))
-					for i := range nodes {
-						nodes[i] = doc.NewNode(imports[i], imports[i], doc.BRANCH, "", true)
-
-						if gf == nil {
-							continue
-						}
-
-						// Check if user specified the version.
-						if v, err := gf.GetValue("deps", imports[i]); err == nil &&
-							len(v) > 0 {
-							nodes[i].Type, nodes[i].Value = validPath(v)
-						}
-					}
-					downloadPackages(ctx, nodes)
+		if downloadCache[n.RootPath] {
+			log.Trace("Skipped downloaded package: %s@%s:%s",
+				n.ImportPath, n.Type, doc.CheckNodeValue(n.Value))
+			continue
+		}
+
+		// Download package.
+		nod, imports := downloadPackage(ctx, n)
+		if len(imports) > 0 {
+			var gf *goconfig.ConfigFile
+
+			// Check if has gopmfile.
+			if com.IsFile(installPath + "/" + doc.GOPM_FILE_NAME) {
+				log.Log("Found gopmfile: %s@%s:%s",
+					n.ImportPath, n.Type, doc.CheckNodeValue(n.Value))
+				gf = doc.NewGopmfile(installPath)
+			}
+
+			// Need to download dependencies.
+			// Generate temporary nodes.
+			nodes := make([]*doc.Node, len(imports))
+			for i := range nodes {
+				nodes[i] = doc.NewNode(imports[i], imports[i], doc.BRANCH, "", true)
+
+				if gf == nil {
+					continue
 				}
 
-				// Only save package information with specific commit.
-				if nod != nil {
-					// Save record in local nodes.
-					log.Success("SUCC", "GET", fmt.Sprintf("%s@%s:%s",
-						n.ImportPath, n.Type, doc.CheckNodeValue(n.Value)))
-					downloadCount++
-
-					// Only save non-commit node.
-					if len(nod.Value) == 0 && len(nod.Revision) > 0 {
-						doc.LocalNodes.SetValue(nod.RootPath, "value", nod.Revision)
-					}
-
-					if ctx.Bool("gopath") && com.IsExist(installPath) {
-						copyToGopath(installPath, gopathDir)
-						log.Log("Package copied to GOPATH: %s", n.ImportPath)
-					}
+				// Check if user specified the version.
+				if v, err := gf.GetValue("deps", imports[i]); err == nil && len(v) > 0 {
+					nodes[i].Type, nodes[i].Value = validPath(v)
 				}
-			} else {
-				log.Trace("Skipped downloaded package: %s@%s:%s",
-					n.ImportPath, n.Type, doc.CheckNodeValue(n.Value))
 			}
-		} else if n.ImportPath == "C" {
+			downloadPackages(ctx, nodes)
+		}
+
+		// Only save package information with specific commit.
+		if nod == nil {
 			continue
-		} else {
-			// Invalid import path.
-			log.Error("download", "Skipped invalid package: "+fmt.Sprintf("%s@%s:%s",
-				n.ImportPath, n.Type, doc.CheckNodeValue(n.Value)))
-			failConut++
+		}
+
+		// Save record in local nodes.
+		log.Success("SUCC", "GET", fmt.Sprintf("%s@%s:%s",
+			n.ImportPath, n.Type, doc.CheckNodeValue(n.Value)))
+		downloadCount++
+
+		// Only save non-commit node.
+		if len(nod.Value) == 0 && len(nod.Revision) > 0 {
+			doc.LocalNodes.SetValue(nod.RootPath, "value", nod.Revision)
+		}
+
+		if ctx.Bool("gopath") && com.IsExist(installPath) && !ctx.Bool("update") &&
+			len(getVcsName(path.Join(installGopath, nod.RootPath))) == 0 {
+			copyToGopath(installPath, gopathDir)
 		}
 	}
 }
@@ -280,8 +305,23 @@ func downloadPackage(ctx *cli.Context, nod *doc.Node) (*doc.Node, []string) {
 	// Mark as donwloaded.
 	downloadCache[nod.RootPath] = true
 
-	nod.Revision = doc.LocalNodes.MustValue(nod.RootPath, "value")
-	imports, err := doc.PureDownload(nod, installRepoPath, ctx) //CmdGet.Flags)
+	// Check if only need to use VCS tools.
+	var imports []string
+	var err error
+	gopathDir := path.Join(installGopath, nod.RootPath)
+	vcs := getVcsName(gopathDir)
+	if ctx.Bool("update") && ctx.Bool("gopath") && len(vcs) > 0 {
+		err = updateByVcs(vcs, gopathDir)
+		imports = doc.GetAllImports([]string{gopathDir}, nod.RootPath, false)
+	} else {
+		// If package has revision and exist, then just check dependencies.
+		if nod.IsGetDepsOnly {
+			return nod, doc.GetAllImports([]string{path.Join(installRepoPath, nod.RootPath) + versionSuffix(nod.Value)},
+				nod.RootPath, ctx.Bool("example"))
+		}
+		nod.Revision = doc.LocalNodes.MustValue(nod.RootPath, "value")
+		imports, err = doc.PureDownload(nod, installRepoPath, ctx) //CmdGet.Flags)
+	}
 
 	if err != nil {
 		log.Error("get", "Fail to download pakage: "+nod.ImportPath)
@@ -292,3 +332,67 @@ func downloadPackage(ctx *cli.Context, nod *doc.Node) (*doc.Node, []string) {
 	}
 	return nod, imports
 }
+
+func getVcsName(dirPath string) string {
+	switch {
+	case com.IsExist(path.Join(dirPath, ".git")):
+		return "git"
+	case com.IsExist(path.Join(dirPath, ".hg")):
+		return "hg"
+	case com.IsExist(path.Join(dirPath, ".svn")):
+		return "svn"
+	}
+	return ""
+}
+
+func updateByVcs(vcs, dirPath string) error {
+	err := os.Chdir(dirPath)
+	if err != nil {
+		log.Error("Update by VCS", "Fail to change work directory:")
+		log.Fatal("", "\t"+err.Error())
+	}
+	defer os.Chdir(workDir)
+
+	switch vcs {
+	case "git":
+		stdout, _, err := com.ExecCmd("git", "status")
+		if err != nil {
+			log.Error("", "Error occurs when 'git status'")
+			log.Error("", "\t"+err.Error())
+		}
+
+		i := strings.Index(stdout, "\n")
+		if i == -1 {
+			log.Error("", "Empty result for 'git status'")
+			return nil
+		}
+
+		branch := strings.TrimPrefix(stdout[:i], "# On branch ")
+		_, _, err = com.ExecCmd("git", "pull", "origin", branch)
+		if err != nil {
+			log.Error("", "Error occurs when 'git pull origin "+branch+"'")
+			log.Error("", "\t"+err.Error())
+		}
+	case "hg":
+		_, stderr, err := com.ExecCmd("hg", "pull")
+		if err != nil {
+			log.Error("", "Error occurs when 'hg pull'")
+			log.Error("", "\t"+err.Error())
+		}
+		if len(stderr) > 0 {
+			log.Error("", "Error: "+stderr)
+		}
+
+		_, stderr, err = com.ExecCmd("hg", "up")
+		if err != nil {
+			log.Error("", "Error occurs when 'hg up'")
+			log.Error("", "\t"+err.Error())
+		}
+		if len(stderr) > 0 {
+			log.Error("", "Error: "+stderr)
+		}
+	case "svn":
+		log.Error("", "Error: not support svn yet")
+	}
+	return nil
+}
diff --git a/cmd/gopath.go b/cmd/gopath.go
index 124906e77..9a32398ee 100644
--- a/cmd/gopath.go
+++ b/cmd/gopath.go
@@ -101,7 +101,7 @@ func getChildPkgs(ctx *cli.Context, cpath string, ppkg *doc.Pkg, cachePkgs map[s
 				if pkgName != "" && strings.HasPrefix(pkg.ImportPath, pkgName) {
 					newPath = filepath.Join(curPath, strings.TrimPrefix(pkg.ImportPath, pkgName))
 				} else {
-					if !com.IsExist(newPath) {
+					if !com.IsExist(newPath) || ctx.Bool("update") {
 						node := doc.NewNode(pkg.ImportPath, pkg.ImportPath,
 							pkg.Type, pkg.Value, true)
 						nodes := []*doc.Node{node}
diff --git a/doc/struct.go b/doc/struct.go
index 96c538503..02e91b5b4 100644
--- a/doc/struct.go
+++ b/doc/struct.go
@@ -42,6 +42,15 @@ type Pkg struct {
 	Value      string // Branch, tag, commit or local.
 }
 
+// If the package is fixed and no need to updated.
+// For commit, tag and local, it's fixed. For branch
+func (pkg *Pkg) IsFixed() bool {
+	if pkg.Type == BRANCH || len(pkg.Value) == 0 {
+		return false
+	}
+	return true
+}
+
 func (pkg *Pkg) VerString() string {
 	if pkg.Value == "" {
 		return pkg.Type
@@ -59,10 +68,11 @@ func NewDefaultPkg(importPath string) *Pkg {
 
 type Node struct {
 	Pkg
-	DownloadURL string
-	Synopsis    string
-	IsGetDeps   bool
-	Revision    string
+	DownloadURL   string
+	Synopsis      string
+	IsGetDeps     bool
+	IsGetDepsOnly bool
+	Revision      string
 }
 
 func NewNode(importPath, downloadUrl, tp, value string, isGetDeps bool) *Node {
diff --git a/gopm.go b/gopm.go
index 9bf0c7d64..f58d1663a 100644
--- a/gopm.go
+++ b/gopm.go
@@ -1,4 +1,4 @@
-// Copyright 2013 gopm authors.
+// Copyright 2013-2014 gopm authors.
 //
 // Licensed under the Apache License, Version 2.0 (the "License"): you may
 // not use this file except in compliance with the License. You may obtain
@@ -12,7 +12,7 @@
 // License for the specific language governing permissions and limitations
 // under the License.
 
-// gopm(Go Package Manager) is a Go package manage tool for search, install, update and share packages in Go.
+// gopm(Go Package Manager) is a Go package manage tool for searching, installing, updating and sharing your packages in Go.
 package main
 
 import (
@@ -29,7 +29,7 @@ import (
 // Test that go1.1 tag above is included in builds. main.go refers to this definition.
 const go11tag = true
 
-const APP_VER = "0.6.0.1210"
+const APP_VER = "0.6.1.0110"
 
 // 	//cmd.CmdSearch,
 // 		cmdClean,
@@ -37,7 +37,6 @@ const APP_VER = "0.6.0.1210"
 // 		cmdEnv,
 // 		cmdFix,
 // 		cmdList,
-// 		cmdTest,
 // 		cmdTool,
 // 		cmdVet,
 // }