diff --git a/doc/walker.go b/doc/walker.go
index b5cce47e7..31ee21b77 100644
--- a/doc/walker.go
+++ b/doc/walker.go
@@ -28,13 +28,8 @@ import (
 	"path"
 	"runtime"
 	"strings"
-	/*
-		"fmt"
-			"regexp"
-			"time"*/
 
-	//"github.com/GPMGo/gpm/models"
-	//"github.com/GPMGo/gpm/utils"
+	"github.com/GPMGo/gpm/utils"
 )
 
 type sliceWriter struct{ p *[]byte }
@@ -139,9 +134,11 @@ func (w *walker) build(srcs []*source) ([]string, error) {
 	}
 
 	var imports []string
-	/*	for _, v := range bpkg.Imports {
+	for _, v := range bpkg.Imports {
 		// Skip strandard library.
-
-	}*/
+		if !utils.IsGoRepoPath(v) {
+			imports = append(imports, v)
+		}
+	}
 	return imports, err
 }
diff --git a/utils/utils.go b/utils/utils.go
index 4f3471343..a51c4e612 100644
--- a/utils/utils.go
+++ b/utils/utils.go
@@ -381,3 +381,152 @@ func GetGOPATH() []string {
 	}
 	return paths
 }
+
+var standardPath = map[string]bool{
+	"builtin": true,
+
+	// go list -f '"{{.ImportPath}}": true,'  std | grep -v 'cmd/|exp/'
+	"cmd/api":             true,
+	"cmd/cgo":             true,
+	"cmd/fix":             true,
+	"cmd/go":              true,
+	"cmd/godoc":           true,
+	"cmd/gofmt":           true,
+	"cmd/vet":             true,
+	"cmd/yacc":            true,
+	"archive/tar":         true,
+	"archive/zip":         true,
+	"bufio":               true,
+	"bytes":               true,
+	"compress/bzip2":      true,
+	"compress/flate":      true,
+	"compress/gzip":       true,
+	"compress/lzw":        true,
+	"compress/zlib":       true,
+	"container/heap":      true,
+	"container/list":      true,
+	"container/ring":      true,
+	"crypto":              true,
+	"crypto/aes":          true,
+	"crypto/cipher":       true,
+	"crypto/des":          true,
+	"crypto/dsa":          true,
+	"crypto/ecdsa":        true,
+	"crypto/elliptic":     true,
+	"crypto/hmac":         true,
+	"crypto/md5":          true,
+	"crypto/rand":         true,
+	"crypto/rc4":          true,
+	"crypto/rsa":          true,
+	"crypto/sha1":         true,
+	"crypto/sha256":       true,
+	"crypto/sha512":       true,
+	"crypto/subtle":       true,
+	"crypto/tls":          true,
+	"crypto/x509":         true,
+	"crypto/x509/pkix":    true,
+	"database/sql":        true,
+	"database/sql/driver": true,
+	"debug/dwarf":         true,
+	"debug/elf":           true,
+	"debug/gosym":         true,
+	"debug/macho":         true,
+	"debug/pe":            true,
+	"encoding/ascii85":    true,
+	"encoding/asn1":       true,
+	"encoding/base32":     true,
+	"encoding/base64":     true,
+	"encoding/binary":     true,
+	"encoding/csv":        true,
+	"encoding/gob":        true,
+	"encoding/hex":        true,
+	"encoding/json":       true,
+	"encoding/pem":        true,
+	"encoding/xml":        true,
+	"errors":              true,
+	"expvar":              true,
+	"flag":                true,
+	"fmt":                 true,
+	"go/ast":              true,
+	"go/build":            true,
+	"go/doc":              true,
+	"go/format":           true,
+	"go/parser":           true,
+	"go/printer":          true,
+	"go/scanner":          true,
+	"go/token":            true,
+	"hash":                true,
+	"hash/adler32":        true,
+	"hash/crc32":          true,
+	"hash/crc64":          true,
+	"hash/fnv":            true,
+	"html":                true,
+	"html/template":       true,
+	"image":               true,
+	"image/color":         true,
+	"image/draw":          true,
+	"image/gif":           true,
+	"image/jpeg":          true,
+	"image/png":           true,
+	"index/suffixarray":   true,
+	"io":                  true,
+	"io/ioutil":           true,
+	"log":                 true,
+	"log/syslog":          true,
+	"math":                true,
+	"math/big":            true,
+	"math/cmplx":          true,
+	"math/rand":           true,
+	"mime":                true,
+	"mime/multipart":      true,
+	"net":                 true,
+	"net/http":            true,
+	"net/http/cgi":        true,
+	"net/http/cookiejar":  true,
+	"net/http/fcgi":       true,
+	"net/http/httptest":   true,
+	"net/http/httputil":   true,
+	"net/http/pprof":      true,
+	"net/mail":            true,
+	"net/rpc":             true,
+	"net/rpc/jsonrpc":     true,
+	"net/smtp":            true,
+	"net/textproto":       true,
+	"net/url":             true,
+	"os":                  true,
+	"os/exec":             true,
+	"os/signal":           true,
+	"os/user":             true,
+	"path":                true,
+	"path/filepath":       true,
+	"reflect":             true,
+	"regexp":              true,
+	"regexp/syntax":       true,
+	"runtime":             true,
+	"runtime/cgo":         true,
+	"runtime/debug":       true,
+	"runtime/pprof":       true,
+	"sort":                true,
+	"strconv":             true,
+	"strings":             true,
+	"sync":                true,
+	"sync/atomic":         true,
+	"syscall":             true,
+	"testing":             true,
+	"testing/iotest":      true,
+	"testing/quick":       true,
+	"text/scanner":        true,
+	"text/tabwriter":      true,
+	"text/template":       true,
+	"text/template/parse": true,
+	"time":                true,
+	"unicode":             true,
+	"unicode/utf16":       true,
+	"unicode/utf8":        true,
+	"unsafe":              true,
+}
+
+// IsGoRepoPath returns true if package is from standard library
+func IsGoRepoPath(importPath string) bool {
+	return standardPath[importPath]
+}