diff --git a/models/oauth2.go b/models/oauth2.go
index 45728b0d51..e50d4039fd 100644
--- a/models/oauth2.go
+++ b/models/oauth2.go
@@ -4,7 +4,11 @@
 
 package models
 
-import "errors"
+import (
+	"errors"
+
+	"github.com/gogits/gogs/modules/log"
+)
 
 // OT: Oauth2 Type
 const (
@@ -16,17 +20,23 @@ const (
 var (
 	ErrOauth2RecordNotExists       = errors.New("not exists oauth2 record")
 	ErrOauth2NotAssociatedWithUser = errors.New("not associated with user")
+	ErrOauth2NotExist              = errors.New("not exist oauth2")
 )
 
 type Oauth2 struct {
 	Id       int64
-	Uid      int64  // userId
+	Uid      int64  `xorm:"unique(s)"` // userId
 	User     *User  `xorm:"-"`
-	Type     int    `xorm:"pk unique(oauth)"` // twitter,github,google...
-	Identity string `xorm:"pk unique(oauth)"` // id..
+	Type     int    `xorm:"unique(s) unique(oauth)"` // twitter,github,google...
+	Identity string `xorm:"unique(s) unique(oauth)"` // id..
 	Token    string `xorm:"VARCHAR(200) not null"`
 }
 
+func BindUserOauth2(userId, oauthId int64) error {
+	_, err := orm.Id(oauthId).Update(&Oauth2{Uid: userId})
+	return err
+}
+
 func AddOauth2(oa *Oauth2) (err error) {
 	if _, err = orm.Insert(oa); err != nil {
 		return err
@@ -47,3 +57,16 @@ func GetOauth2(identity string) (oa *Oauth2, err error) {
 	oa.User, err = GetUserById(oa.Uid)
 	return oa, err
 }
+
+func GetOauth2ById(id int64) (oa *Oauth2, err error) {
+	oa = new(Oauth2)
+	has, err := orm.Id(id).Get(oa)
+	log.Info("oa: %v", oa)
+	if err != nil {
+		return nil, err
+	}
+	if !has {
+		return nil, ErrOauth2NotExist
+	}
+	return oa, nil
+}
diff --git a/routers/user/social.go b/routers/user/social.go
index 2b60ab9ffd..8568bc2af8 100644
--- a/routers/user/social.go
+++ b/routers/user/social.go
@@ -22,10 +22,9 @@ import (
 
 type SocialConnector interface {
 	Identity() string
-	Type() int
 	Name() string
 	Email() string
-	Token() string
+	TokenString() string
 }
 
 type SocialGithub struct {
@@ -34,17 +33,13 @@ type SocialGithub struct {
 		Name  string `json:"login"`
 		Email string `json:"email"`
 	}
-	WebToken *oauth.Token
+	Token *oauth.Token
 }
 
 func (s *SocialGithub) Identity() string {
 	return strconv.Itoa(s.data.Id)
 }
 
-func (s *SocialGithub) Type() int {
-	return models.OT_GITHUB
-}
-
 func (s *SocialGithub) Name() string {
 	return s.data.Name
 }
@@ -53,8 +48,8 @@ func (s *SocialGithub) Email() string {
 	return s.data.Email
 }
 
-func (s *SocialGithub) Token() string {
-	data, _ := json.Marshal(s.WebToken)
+func (s *SocialGithub) TokenString() string {
+	data, _ := json.Marshal(s.Token)
 	return string(data)
 }
 
@@ -62,7 +57,7 @@ func (s *SocialGithub) Token() string {
 func (s *SocialGithub) Update() error {
 	scope := "https://api.github.com/user"
 	transport := &oauth.Transport{
-		Token: s.WebToken,
+		Token: s.Token,
 	}
 	log.Debug("update github info")
 	r, err := transport.Client().Get(scope)
@@ -122,7 +117,7 @@ func SocialSignIn(ctx *middleware.Context, tokens oauth2.Tokens) {
 	next = extractPath(ctx.Query("state"))
 	log.Debug("success token: %v", tk)
 
-	gh := &SocialGithub{WebToken: tk}
+	gh := &SocialGithub{Token: tk}
 	if err = gh.Update(); err != nil {
 		// FIXME: handle error page 501
 		log.Error("connect with github error: %s", err)
@@ -137,9 +132,9 @@ func SocialSignIn(ctx *middleware.Context, tokens oauth2.Tokens) {
 		ctx.Session.Set("userName", oa.User.Name)
 	case models.ErrOauth2RecordNotExists:
 		oa = &models.Oauth2{}
-		oa.Uid = 0
-		oa.Type = soc.Type()
-		oa.Token = soc.Token()
+		oa.Uid = -1
+		oa.Type = models.OT_GITHUB
+		oa.Token = soc.TokenString()
 		oa.Identity = soc.Identity()
 		log.Debug("oa: %v", oa)
 		if err = models.AddOauth2(oa); err != nil {
@@ -147,7 +142,11 @@ func SocialSignIn(ctx *middleware.Context, tokens oauth2.Tokens) {
 			return
 		}
 	case models.ErrOauth2NotAssociatedWithUser:
-		// ignore it. judge in /usr/login page
+		ctx.Session.Set("socialName", soc.Name())
+		ctx.Session.Set("socialEmail", soc.Email())
+		ctx.Session.Set("socialId", oa.Id)
+		ctx.Redirect("/user/sign_up")
+		return
 	default:
 		log.Error(err.Error()) // FIXME: handle error page
 		return
diff --git a/routers/user/user.go b/routers/user/user.go
index 37c6baa9f2..0d9f67e497 100644
--- a/routers/user/user.go
+++ b/routers/user/user.go
@@ -82,6 +82,7 @@ func SignIn(ctx *middleware.Context) {
 		ctx.Data["OauthGitHubEnabled"] = base.OauthService.GitHub.Enabled
 	}
 
+	var user *models.User
 	// Check auto-login.
 	userName := ctx.GetCookie(base.CookieUserName)
 	if len(userName) == 0 {
@@ -90,15 +91,17 @@ func SignIn(ctx *middleware.Context) {
 	}
 
 	isSucceed := false
+	var err error
 	defer func() {
 		if !isSucceed {
 			log.Trace("%s auto-login cookie cleared: %s", ctx.Req.RequestURI, userName)
 			ctx.SetCookie(base.CookieUserName, "", -1)
 			ctx.SetCookie(base.CookieRememberName, "", -1)
+			return
 		}
 	}()
 
-	user, err := models.GetUserByName(userName)
+	user, err = models.GetUserByName(userName)
 	if err != nil {
 		ctx.HTML(200, "user/signin")
 		return
@@ -112,6 +115,7 @@ func SignIn(ctx *middleware.Context) {
 	}
 
 	isSucceed = true
+
 	ctx.Session.Set("userId", user.Id)
 	ctx.Session.Set("userName", user.Name)
 	if redirectTo, _ := url.QueryUnescape(ctx.GetCookie("redirect_to")); len(redirectTo) > 0 {
@@ -155,6 +159,13 @@ func SignInPost(ctx *middleware.Context, form auth.LogInForm) {
 		ctx.SetSecureCookie(secret, base.CookieRememberName, user.Name, days)
 	}
 
+	// Bind with social account
+	if sid, ok := ctx.Session.Get("socialId").(int64); ok {
+		if err = models.BindUserOauth2(user.Id, sid); err != nil {
+			log.Error("bind user error: %v", err)
+		}
+		ctx.Session.Delete("socialId")
+	}
 	ctx.Session.Set("userId", user.Id)
 	ctx.Session.Set("userName", user.Name)
 	if redirectTo, _ := url.QueryUnescape(ctx.GetCookie("redirect_to")); len(redirectTo) > 0 {
@@ -169,6 +180,7 @@ func SignInPost(ctx *middleware.Context, form auth.LogInForm) {
 func SignOut(ctx *middleware.Context) {
 	ctx.Session.Delete("userId")
 	ctx.Session.Delete("userName")
+	ctx.Session.Delete("socialId")
 	ctx.SetCookie(base.CookieUserName, "", -1)
 	ctx.SetCookie(base.CookieRememberName, "", -1)
 	ctx.Redirect("/")
@@ -178,11 +190,23 @@ func SignUp(ctx *middleware.Context) {
 	ctx.Data["Title"] = "Sign Up"
 	ctx.Data["PageIsSignUp"] = true
 
+	if sid, ok := ctx.Session.Get("socialId").(int64); ok {
+		var err error
+		if _, err = models.GetOauth2ById(sid); err == nil {
+			ctx.Data["IsSocialLogin"] = true
+			// FIXME: don't set in error page
+			ctx.Data["username"] = ctx.Session.Get("socialName")
+			ctx.Data["email"] = ctx.Session.Get("socialEmail")
+		} else {
+			log.Error("unaccepted oauth error: %s", err) // FIXME: should it show in page
+		}
+	}
 	if base.Service.DisenableRegisteration {
 		ctx.Data["DisenableRegisteration"] = true
 		ctx.HTML(200, "user/signup")
 		return
 	}
+	log.Info("session: %v", ctx.Session.Get("socialId"))
 
 	ctx.HTML(200, "user/signup")
 }
@@ -232,6 +256,11 @@ func SignUpPost(ctx *middleware.Context, form auth.RegisterForm) {
 	}
 
 	log.Trace("%s User created: %s", ctx.Req.RequestURI, strings.ToLower(form.UserName))
+	// Bind Social Account
+	if sid, ok := ctx.Session.Get("socialId").(int64); ok {
+		models.BindUserOauth2(u.Id, sid)
+		ctx.Session.Delete("socialId")
+	}
 
 	// Send confirmation e-mail.
 	if base.Service.RegisterEmailConfirm && u.Id > 1 {
diff --git a/templates/user/signin.tmpl b/templates/user/signin.tmpl
index 294c0d3418..a06e3ca8a0 100644
--- a/templates/user/signin.tmpl
+++ b/templates/user/signin.tmpl
@@ -46,9 +46,9 @@
         {{if .OauthEnabled}}
         <div class="form-group text-center" id="social-login">
             <h4>Log In with Social Accounts</h4>
-            {{if .OauthGitHubEnabled}}<a href="/user/login/github"><i class="fa fa-github-square fa-3x"></i></a>{{end}}
+            {{if .OauthGitHubEnabled}}<a href="/user/login/github?next=/user/sign_up"><i class="fa fa-github-square fa-3x"></i></a>{{end}}
         </div>
         {{end}}
     </form>
 </div>
-{{template "base/footer" .}}
\ No newline at end of file
+{{template "base/footer" .}}
diff --git a/templates/user/signup.tmpl b/templates/user/signup.tmpl
index 87fa80ccc1..b12333a257 100644
--- a/templates/user/signup.tmpl
+++ b/templates/user/signup.tmpl
@@ -6,19 +6,24 @@
 		{{if .DisenableRegisteration}}
 		Sorry, registeration has been disenabled, you can only get account from administrator.
 		{{else}}
-        <h3>Sign Up</h3>
+		{{if .IsSocialLogin}}
+			<h3>Social login: 2nd step <small>complete information</small></h3>
+		{{else}}
+			<h3>Sign Up</h3>
+		{{end}}
 	    {{template "base/alert" .}}
+		{{if .IsSocialLogin}}
+		{{end}}
 		<div class="form-group {{if .Err_UserName}}has-error has-feedback{{end}}">
 			<label class="col-md-4 control-label">Username: </label>
 			<div class="col-md-6">
 				<input name="username" class="form-control" placeholder="Type your username" value="{{.username}}" required="required">
 			</div>
 		</div>
-
 		<div class="form-group {{if .Err_Email}}has-error has-feedback{{end}}">
 			<label class="col-md-4 control-label">Email: </label>
 			<div class="col-md-6">
-				<input name="email" class="form-control" placeholder="Type your e-mail address" value="{{.email}}" required="required" title="Email is not valid">
+				<input name="email" class="form-control" placeholder="Type your e-mail address" value="{{.email}}{{.socialEmail}}" required="required" title="Email is not valid">
 			</div>
 		</div>
 
@@ -44,10 +49,14 @@
 		
 	    <div class="form-group">
             <div class="col-md-offset-4 col-md-6">
+			{{if .IsSocialLogin}}
+                <a href="/user/login">Already have an account? Bind now!</a>
+			{{else}}
                 <a href="/user/login">Already have an account? Sign in now!</a>
+			{{end}}
             </div>
 	    </div>
 	    {{end}}
 	</form>
 </div>
-{{template "base/footer" .}}
\ No newline at end of file
+{{template "base/footer" .}}