diff --git a/src/main/java/com/example/cosmos_serversb/entities/Group.java b/src/main/java/com/example/cosmos_serversb/entities/Group.java
index 7b2805b..485306b 100644
--- a/src/main/java/com/example/cosmos_serversb/entities/Group.java
+++ b/src/main/java/com/example/cosmos_serversb/entities/Group.java
@@ -87,7 +87,6 @@
     }
 
     public void addMember(String uId){
-        // User user = new User(uId, uId, "http:test", "hogehoge");
         User user = Users.getInstance().getUserById(uId);
         if(user != null) {
             members.add(user);
diff --git a/src/main/java/com/example/cosmos_serversb/models/Groups.java b/src/main/java/com/example/cosmos_serversb/models/Groups.java
index eb3a1ff..5307dba 100644
--- a/src/main/java/com/example/cosmos_serversb/models/Groups.java
+++ b/src/main/java/com/example/cosmos_serversb/models/Groups.java
@@ -53,12 +53,6 @@
         Group testGroup = new Group(gId, uri, name, uId);
         Session session = SessionManager.getInstance().getSession();
         session.save(testGroup);
-//        SessionManager.getInstance().closeSession();
-//        session = SessionManager.getSession().getSession();
-//        testGroup.addMember(uId);
-//        int n = testGroup.getMembers().size();
-//        session.update(testGroup);
-//        SessionManager.getInstance().closeSession();
         return testGroup;
     }
 
@@ -90,7 +84,13 @@
     }
 
     public static HashMap<String, String> addMember(String gId, String uId){
-        return null;
+        Session session = SessionManager.getInstance().getSession();
+        Group editGroup = session.load(Group.class, gId);//取得できない
+        if(editGroup != null) {
+            editGroup.addMember(uId);
+            session.update(editGroup);
+        }
+        return null;//HashMapへの変更が必要
     }
 
     public static HashMap<String, String> deleteMember(String gId, String uId){
@@ -138,17 +138,6 @@
          */
     }
 
-    //とりあえず作成。あとでaddMember()と統合させる。
-    public static void addMemberWhenCreateGroup(Group editGroup, String uId){
-          Session session = SessionManager.getInstance().getSession();
-//          Group editGroup = session.load(Group.class, "gId");//取得できない
-          if(editGroup != null) {
-              editGroup.addMember(uId);
-//            int n = testGroup.getMembers().size();
-              session.update(editGroup);
-          }
-    }
-
     public static HashMap<String, String> getTestHashMap(){
         return testMap;
     }
diff --git a/src/main/java/com/example/cosmos_serversb/resources/GroupsRest.java b/src/main/java/com/example/cosmos_serversb/resources/GroupsRest.java
index 31ab036..0ad7fe3 100644
--- a/src/main/java/com/example/cosmos_serversb/resources/GroupsRest.java
+++ b/src/main/java/com/example/cosmos_serversb/resources/GroupsRest.java
@@ -29,15 +29,14 @@
         //グループの作成
         SessionManager.getInstance().getSession();
         ObjectMapper mapper = new ObjectMapper();
-        String json = mapper.writeValueAsString(Groups.getInstance().createGroup(name, uId));
-        SessionManager.getInstance().closeSession();
+        Group group = Groups.getInstance().createGroup(name, uId);
+        SessionManager.getInstance().closeSession();//一度データベースを更新。
 
         //グループにメンバーの追加
         SessionManager.getInstance().getSession();
-        Group group = mapper.readValue(json, Group.class);
-//        Groups.addMemberById(group.getgId(), uId);//どうやってこのgIdを取得する？
-        Groups.addMemberWhenCreateGroup(group, uId);
+        Groups.addMember(group.getgId(), uId);
         SessionManager.getInstance().closeSession();
+        String json = mapper.writeValueAsString(group);
         return json;
     }