diff --git a/MyLocalChat/src/main/java/domain/ChatRoom.java b/MyLocalChat/src/main/java/domain/ChatRoom.java
index 564ddab..85ff85c 100644
--- a/MyLocalChat/src/main/java/domain/ChatRoom.java
+++ b/MyLocalChat/src/main/java/domain/ChatRoom.java
@@ -7,7 +7,6 @@ import java.util.List;
 public class ChatRoom {
     private static int nextRoomId = 1000;
     private int roomId;
-    private String roomName;
     private List<Message> messages;
     private final LocalDateTime createdAt;
     private User user1;
@@ -20,9 +19,6 @@ public class ChatRoom {
         this.user1 = user1;
         this.user2 = user2;
     }
-    
-   
-
     public void addMessage(Message message) {
         if (messages == null) 
             messages = new ArrayList<>();
diff --git a/MyLocalChat/src/main/java/domain/GruppenRoom.java b/MyLocalChat/src/main/java/domain/GruppenRoom.java
index 35fd1fb..0a72fbd 100644
--- a/MyLocalChat/src/main/java/domain/GruppenRoom.java
+++ b/MyLocalChat/src/main/java/domain/GruppenRoom.java
@@ -1,5 +1,37 @@
 package domain;
 
+import java.time.LocalDateTime;
+import java.util.ArrayList;
+import java.util.List;
+
 public class GruppenRoom {
+	private User creater;
+	private List<User> roots;
+	private List<User> participants;
+	private String description;
+	private String name;
+	private List<Message> messages;
+	private final LocalDateTime createdAt;
+	
+	public GruppenRoom(User creater, String description, String name) {
+		super();
+		this.creater = creater;
+		this.description = description;
+		this.name = name;
+		this.createdAt = LocalDateTime.now();
+		
+		this.roots = new ArrayList<>();
+		this.participants = new ArrayList<>();
+		this.messages = new ArrayList<>();
+		
+		this.roots.add(creater);
+		this.participants.add(creater);
+	}
+	
+	public boolean addparticipants(User user) {
+		return participants.add(user);
+	}
+	
+	
 
 }
diff --git a/MyLocalChat/src/main/java/domain/User.java b/MyLocalChat/src/main/java/domain/User.java
index 1f8701c..3920a90 100644
--- a/MyLocalChat/src/main/java/domain/User.java
+++ b/MyLocalChat/src/main/java/domain/User.java
@@ -10,8 +10,8 @@ public class User {
 	private UserInfo userInfo;
 	private UserContacts userContacts;
 	private UserChatRoom chatRoom;
-	private List<GruppenRoom> userGruppen;
-
+	private UserGruppenRoom gruppenRoom;
+	
 	public User(String username) {
 		this.userId = nextUserId++;
 		this.username = username;
@@ -19,6 +19,7 @@ public class User {
 		this.userInfo = UserInfo.VERFÜGBAR;
 		this.userContacts = new UserContacts();
 		this.chatRoom = new UserChatRoom();
+		this.gruppenRoom = new UserGruppenRoom();
 
 	}
 
@@ -53,6 +54,10 @@ public class User {
 	public UserChatRoom getUserChatRoom() {
 		return chatRoom;
 	}
+	
+	public UserGruppenRoom getUserGruppenRoom() {
+		return gruppenRoom;
+	}
 
 	@Override
 	public String toString() {
diff --git a/MyLocalChat/src/main/java/domain/UserGruppenRoom.java b/MyLocalChat/src/main/java/domain/UserGruppenRoom.java
new file mode 100644
index 0000000..ff9aed5
--- /dev/null
+++ b/MyLocalChat/src/main/java/domain/UserGruppenRoom.java
@@ -0,0 +1,17 @@
+package domain;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class UserGruppenRoom {
+	private List<GruppenRoom> gruppenRooms;
+	
+	public UserGruppenRoom() {
+		this.gruppenRooms = new ArrayList<>();
+	}
+	
+	public boolean addGroupproom(GruppenRoom gruppenRoom) {
+		return gruppenRooms.add(gruppenRoom);
+	}
+
+}