diff --git a/core/service.go b/core/service.go
index bd6a351..e583c4f 100644
--- a/core/service.go
+++ b/core/service.go
@@ -1,7 +1,6 @@
 package core
 
 import (
-	"context"
 	"crypto/md5"
 	"encoding/hex"
 	"encoding/json"
@@ -455,6 +454,7 @@ func (sh *serviceDescription) unlink(w http.ResponseWriter, r *http.Request) {
 	sType := queryvals.Get("stype")
 	sId := queryvals.Get("sid")
 	sk := queryvals.Get("sk")
+	targetType := queryvals.Get("ttype")
 
 	authInfo, err := sh.sessionProvider.Query(sk)
 	if err != nil {
@@ -471,44 +471,51 @@ func (sh *serviceDescription) unlink(w http.ResponseWriter, r *http.Request) {
 	// fmt.Println(authInfo.Uid)
 	// fmt.Println("=================")
 
+	sType, sId, err = sh.getProviderInfo(sType, sId)
+	if err != nil {
+		logger.Println("getProviderInfo failed :", err)
+		w.WriteHeader(http.StatusBadRequest)
+		return
+	}
+
 	if authInfo.Uid != sId || authInfo.Platform != sType {
 		logger.Println("unlink failed. session key is not correct :", authInfo, queryvals)
 		w.WriteHeader(http.StatusBadRequest)
 		return
 	}
 
-	numRecord, err := sh.mongoClient.Collection(CollectionAccount).CountDocuments(context.Background(), bson.M{
+	accDocs, err := sh.mongoClient.FindAll(CollectionAccount, bson.M{
 		"accid": authInfo.Account,
-	}, options.Count().SetLimit(2))
-
+	}, options.Find().SetProjection(bson.M{
+		"_id": 1,
+	}))
 	if err != nil {
 		logger.Error("unlink failed, fail to count accounts :", err)
 		w.WriteHeader(http.StatusBadRequest)
 	}
 
-	if numRecord <= 1 {
+	if len(accDocs) <= 1 {
 		logger.Println("unlink failed. At least one link must be maintained. :", r.URL.Query())
 		w.WriteHeader(http.StatusBadRequest)
 		return
 	}
 
-	sType, sId, err = sh.getProviderInfo(sType, sId)
-	if err != nil {
-		logger.Error("getProviderInfo failed :", err)
-		w.WriteHeader(http.StatusBadRequest)
+	var ids primitive.A
+	for _, accDoc := range accDocs {
+		ids = append(ids, accDoc["_id"].(primitive.ObjectID))
 	}
 
-	link, err := sh.mongoClient.FindOne(CollectionLink, bson.M{
-		"platform": sType,
-		"uid":      sId,
-	}, options.FindOne().SetProjection(bson.M{"_id": 1}))
+	link, err := sh.mongoClient.FindOneAndDelete(CollectionLink, bson.M{
+		"platform": targetType,
+		"_id":      bson.M{"$in": ids},
+	}, options.FindOneAndDelete().SetProjection(bson.M{"_id": 1}))
 	if err != nil {
 		logger.Error("link failed. FindOneAndUpdate link err:", err)
 		w.WriteHeader(http.StatusInternalServerError)
 		return
 	}
 
-	newid, err := sh.mongoClient.FindOneAndDelete(CollectionAccount, bson.M{
+	preid, err := sh.mongoClient.FindOneAndDelete(CollectionAccount, bson.M{
 		"_id": link["_id"].(primitive.ObjectID),
 	}, options.FindOneAndDelete().SetProjection(bson.M{"_id": 1}))
 	if err != nil {
@@ -517,9 +524,7 @@ func (sh *serviceDescription) unlink(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	// newid가 있어야 한다. 그래야 기존 서비스 계정이 없는 상태이다.
-	if newid == nil {
-		// 이미 계정이 있네?
+	if preid == nil {
 		logger.Println("unlink failed. service account not found:", r.URL.Query())
 		w.WriteHeader(http.StatusBadRequest)
 		return
@@ -528,7 +533,7 @@ func (sh *serviceDescription) unlink(w http.ResponseWriter, r *http.Request) {
 	logger.Println("unlink success :", r.URL.Query())
 }
 
-// == 연결된 계정 정보(숫자) 전달하는 API
+// == 연결된 계정 정보(platform) 전달하는 API
 func (sh *serviceDescription) linkinfo(w http.ResponseWriter, r *http.Request) {
 	defer func() {
 		s := recover()
@@ -562,6 +567,13 @@ func (sh *serviceDescription) linkinfo(w http.ResponseWriter, r *http.Request) {
 	// fmt.Println(authInfo.Uid)
 	// fmt.Println("=================")
 
+	sType, sId, err = sh.getProviderInfo(sType, sId)
+	if err != nil {
+		logger.Error("getProviderInfo failed :", err)
+		w.WriteHeader(http.StatusBadRequest)
+		return
+	}
+
 	//if oldAuth.Token != oldToken || oldAuth.Uid != oldId || oldAuth.Platform != oldType {
 	if authInfo.Uid != sId || authInfo.Platform != sType {
 		logger.Println("linkinfo failed. session key is not correct :", authInfo, queryvals)
@@ -569,19 +581,46 @@ func (sh *serviceDescription) linkinfo(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	numRecord, err := sh.mongoClient.Collection(CollectionAccount).CountDocuments(context.Background(), bson.M{
-		"accid": authInfo.Account,
-	}, options.Count().SetLimit(sh.MaximumNumLinkAccount))
-
+	platformName := "platform"
+	accDocs, err := sh.mongoClient.FindAll(CollectionAccount, bson.M{"accid": authInfo.Account}, options.Find().SetLimit(sh.MaximumNumLinkAccount).SetProjection(bson.M{
+		"_id": 1,
+	}))
 	if err != nil {
 		logger.Error("linkinfo failed. CountDocuments err :", err)
-		w.WriteHeader(http.StatusBadRequest)
+		w.WriteHeader(http.StatusInternalServerError)
 		return
 	}
 
-	logger.Println("linkinfo :", numRecord)
-	w.Write([]byte(fmt.Sprintf(`{"num_linked_account":"%d"}`, numRecord)))
+	var ids primitive.A
+	for _, accDoc := range accDocs {
+		ids = append(ids, accDoc["_id"].(primitive.ObjectID))
+	}
 
+	links, err := sh.mongoClient.FindAll(CollectionLink, bson.M{
+		"_id": bson.M{"$in": ids},
+	}, options.Find().SetLimit(sh.MaximumNumLinkAccount).SetProjection(bson.M{
+		platformName: 1,
+	}))
+	if err != nil {
+		logger.Error("linkinfo failed. FindAll returns err :", err)
+		w.WriteHeader(http.StatusInternalServerError)
+		return
+	}
+
+	var linkstrs []string
+	for _, link := range links {
+		linkstrs = append(linkstrs, link[platformName].(string))
+	}
+
+	linkbytes, err := json.Marshal(linkstrs)
+	if err != nil {
+		logger.Error("linkinfo failed. json marshal fail :", err)
+		w.WriteHeader(http.StatusInternalServerError)
+		return
+	}
+
+	logger.Println("linkinfo :", linkstrs)
+	w.Write(linkbytes)
 }
 
 // == 계정 이메일 조회