diff --git a/src/main/java/org/ntlab/acanthus_server/entities/Account.java b/src/main/java/org/ntlab/acanthus_server/entities/Account.java
index cb48a1e..1201294 100644
--- a/src/main/java/org/ntlab/acanthus_server/entities/Account.java
+++ b/src/main/java/org/ntlab/acanthus_server/entities/Account.java
@@ -23,6 +23,7 @@
 import com.fasterxml.jackson.annotation.JsonIgnore;
 
 import java.util.ArrayList;
+import java.util.HashMap;
 import java.util.UUID;
 
 public class Account {
@@ -30,7 +31,7 @@
     private Integer uid;
     private String name;
     private String email;
-    private ArrayList<Work> workList = new ArrayList<>();
+    private HashMap<Integer, Work> workHashMap = new HashMap<>();
 
     @JsonIgnore
     private String token;
@@ -66,7 +67,8 @@
     }
 
     public void addWork(Work work) {
-        this.workList.add(work);
+        //var aid = work.getAid();
+        //this.workList.push(work);
     }
 
     //-----------------------------------------------------------------
@@ -96,22 +98,24 @@
     public ArrayList<Work> getInvitedList() {
         var invitedList = new ArrayList<Work>();
 
-        for (var work : workList){
+        for (var work : workHashMap.values()) {
             if (work.isInviting()) invitedList.add(work);
         }
 
         return invitedList;
     }
+
     //-----------------------------------------------------------------
     // 参加している作品を返す
     public ArrayList<Work> getWorkingList() {
         var workingList = new ArrayList<Work>();
 
-        for (var work : workList) {
+        for (var work : workHashMap.values()) {
             if (work.isWorking()) workingList.add(work);
         }
-         return workingList;
+        return workingList;
     }
+
     //-----------------------------------------------------------------
     //-----------------------------------------------------------------
     // トークンを更新する 藤井