diff --git a/src/main/java/org/ntlab/nemophila/models/accounts/Account.java b/src/main/java/org/ntlab/nemophila/models/accounts/Account.java
index cc51cc5..61edc30 100644
--- a/src/main/java/org/ntlab/nemophila/models/accounts/Account.java
+++ b/src/main/java/org/ntlab/nemophila/models/accounts/Account.java
@@ -22,6 +22,8 @@
     @JsonIgnore
     FriendManager friendManager = new FriendManager();
 
+    private int newPid = 1;
+
     //コンストラクタ
     public Account(String name, String pw) {
         this.name = name;
@@ -62,8 +64,9 @@
     //新規投稿
     public Post createPost(String sid, int rate, String genre, String comment, String image1, String image2, String image3) {
         Post post = new Post(this, genre, rate, sid);
-        //pidの登録
-        post.setId(String.valueOf(posts.size()+1));
+        //pidの登録.始めの投稿が"1"
+        post.setId(String.valueOf(newPid));
+        newPid++;
         //null時「なし」に変換させて登録。
         post.setImage1(image1);
         post.setImage2(image2);
@@ -97,4 +100,4 @@
     public FriendManager getFriendManager() {
         return friendManager;
     }
-}
+}
\ No newline at end of file