diff --git a/FarmEventHandler.java b/FarmEventHandler.java
index db0b928..b8af48b 100644
--- a/FarmEventHandler.java
+++ b/FarmEventHandler.java
@@ -11,7 +11,7 @@ public class FarmEventHandler implements CommandExecutor {
 
     GroupArray m_GroupArray;
     UserInfoArray m_UserInfoArray;
-
+    UUID ZERO_UUID = new UUID(0,0);
     public FarmEventHandler(GroupArray GA, UserInfoArray UIA){
         m_GroupArray = GA;
         m_UserInfoArray = UIA;
@@ -24,21 +24,46 @@ public class FarmEventHandler implements CommandExecutor {
             switch (args[0]) {
                 case "생성":{
                     UUID tempUUID = UUID.randomUUID();
-                    m_GroupArray.CreateGroup(tempUUID, args[1], p.getUniqueId());
-                    m_UserInfoArray.setUserGroupUUID("Party",p.getUniqueId(), tempUUID);
-                    p.sendMessage(args[1]+"농장이 생성되었습니다.");
-                    p.sendMessage("농장 멤버 목록: ");
-                    for (String Name: m_GroupArray.GetGroupMembersName(tempUUID)){
-                        p.sendMessage(Name);
+                    if(m_UserInfoArray.getUserGroupUUID(p.getUniqueId(), "Farm").equals(ZERO_UUID)){
+                        if(m_GroupArray.CreateGroup(tempUUID, args[1], p.getUniqueId())){
+                            m_UserInfoArray.setUserGroupUUID("Farm",p.getUniqueId(), tempUUID);
+                            p.sendMessage(args[1]+"농장이 생성되었습니다.");
+                            p.sendMessage("농장 멤버 목록: ");
+                            for (String Name: m_GroupArray.GetGroupMembersName(tempUUID)){
+                                p.sendMessage(Name);
+                            }
+                            p.sendMessage("농장 목록:");
+                            for (String Name: m_GroupArray.GetGroupNameList()){
+                                p.sendMessage(Name);
+                            }
+                        }
+                        else{
+                            p.sendMessage("이미 존재하는 농장 이름");
+                        }
                     }
-                    p.sendMessage("농장 목록:");
-                    for (String Name: m_GroupArray.GetGroupNameList()){
-                        p.sendMessage(Name);
+                    else{
+                        p.sendMessage("이미 농장을 소유중"+m_UserInfoArray.getUserGroupUUID(p.getUniqueId(), "Farm"));
                     }
                     break;
                 }
                 case "가입":{
-                    p.sendMessage("가입 테스트");
+                    p.sendMessage("플레이어 UUID:"+p.getUniqueId()+"  농장 UUID:"+m_UserInfoArray.getUserGroupUUID(p.getUniqueId(), "Farm"));
+                    p.sendMessage("ZERO UUID:"+ZERO_UUID);
+                    if(!m_UserInfoArray.getUserGroupUUID(p.getUniqueId(), "Farm").equals(ZERO_UUID)){
+                        p.sendMessage("이미 가입한 농장이 존재");
+                    }
+                    else{
+                        p.sendMessage("가입 완료");
+                        m_GroupArray.SignUpGroup("Farm",m_GroupArray.m_GroupNameList.get(args[1]),p.getUniqueId());
+                        p.sendMessage("농장 멤버 목록: ");
+                        for (String Name: m_GroupArray.GetGroupMembersName(m_GroupArray.m_GroupNameList.get(args[1]))){
+                            p.sendMessage(Name);
+                        }
+                        p.sendMessage("농장 목록:");
+                        for (String Name: m_GroupArray.GetGroupNameList()){
+                            p.sendMessage(Name);
+                        }
+                    }
                     break;
                 }
                 case "초대":{
@@ -49,10 +74,29 @@ public class FarmEventHandler implements CommandExecutor {
                     p.sendMessage("강퇴 테스트");
                     break;
                 }
+                case "탈퇴": {
+                    if(!m_UserInfoArray.getUserGroupUUID(p.getUniqueId(), "Farm").equals(ZERO_UUID)){
+                        m_GroupArray.ExpulsionGroupPlayer("Farm",m_UserInfoArray.getUserGroupUUID(p.getUniqueId(),"Farm"),p.getUniqueId());
+                    }
+                    else{
+                        p.sendMessage("가입한 농장이 없습니다."+m_UserInfoArray.getUserGroupUUID(p.getUniqueId(), "Farm"));
+                    }
+                    break;
+                }
                 case "이름":{
                     p.sendMessage("현재 파티 이름"+m_GroupArray.GetGroupName(m_UserInfoArray.getUserGroupUUID(p.getUniqueId(),"Party")));
                     break;
                 }
+                case "정보": {
+                    for (String Name: m_GroupArray.GetGroupNameList()){
+                        p.sendMessage("농장 이름:");
+                        p.sendMessage(Name);
+                        p.sendMessage("인원 목록");
+                        for (String Name2: m_GroupArray.GetGroupMembersName(m_GroupArray.m_GroupNameList.get(Name))) {
+                            p.sendMessage(Name2);
+                        }
+                    }
+                }
             }
         }
         return true;
diff --git a/Group.java b/Group.java
index 38f7b7e..f56be02 100644
--- a/Group.java
+++ b/Group.java
@@ -27,7 +27,7 @@ public class Group {
 
     public List<UUID> getGroupMembers(){ return m_MemberList;}
     public String getGroupName(){ return m_Name; }
-
+    public int isEmpty(){return m_MemberList.size();}
     public boolean isOwner(UUID uuid){
         if(m_MemberList.get(0)==uuid){
             return true;
diff --git a/GroupArray.java b/GroupArray.java
index 71c3728..bd8086d 100644
--- a/GroupArray.java
+++ b/GroupArray.java
@@ -5,12 +5,12 @@ import org.bukkit.Bukkit;
 import java.util.*;
 
 public class GroupArray {
-    private static Map<UUID, Group> m_GroupArray = new HashMap<UUID, Group>();
+    public static Map<UUID, Group> m_GroupArray = new HashMap<UUID, Group>();
 
-    private static Map<String, UUID> m_GroupNameList = new HashMap<String, UUID>();
+    public static Map<String, UUID> m_GroupNameList = new HashMap<String, UUID>();
 
     UserInfoArray m_UserInfoArray;
-
+    UUID ZERO_UUID = UUID.fromString("00000000-0000-0000-0000-000000000000");
     public GroupArray(UserInfoArray m_UIA){
         m_UserInfoArray = m_UIA;
     }
@@ -23,7 +23,18 @@ public class GroupArray {
             return true;
         }
     }
+    public boolean CheckGroup(String GroupType, String Name){
+        return m_GroupArray.containsKey(m_GroupNameList.get(Name));
+    }
+    public static <K, V> K getKey(Map<K, V> map, V value) {
 
+        for (K key : map.keySet()) {
+            if (value.equals(map.get(key))) {
+                return key;
+            }
+        }
+        return null;
+    }
     public boolean DeleteGroup(UUID GroupUUID, String GroupType){
         if(m_GroupArray.containsKey(GroupUUID)){
             for(UUID key: GetGroupMembersUUID(GroupUUID)){
@@ -55,10 +66,15 @@ public class GroupArray {
         }
     }
 
-    public boolean ExpulsionGroupPlayer(UUID GroupUUID, UUID PlayerUUID){
-        if(GetGroupMembersName(GroupUUID).contains(PlayerUUID)) {
+    public boolean ExpulsionGroupPlayer(String GroupType, UUID GroupUUID, UUID PlayerUUID){
+        if(m_GroupArray.get(GroupUUID).isMember(PlayerUUID)) {
             Group m_Group = m_GroupArray.get(GroupUUID);
             m_Group.Expulsion(PlayerUUID);
+            m_UserInfoArray.setUserGroupUUID(GroupType,PlayerUUID,ZERO_UUID);
+            if(m_Group.isEmpty()==0){
+                m_GroupArray.remove(GroupUUID);
+                m_GroupNameList.remove(getKey(m_GroupNameList,GroupUUID));
+            }
             return true;
         } else{
             return false; // Wrong Player Name. FIXME{Need Checking function for a validate user name's }