diff --git a/src/main/java/com/example/oneul/model/Post.java b/src/main/java/com/example/oneul/model/Post.java
new file mode 100644
index 0000000..a0baec3
--- /dev/null
+++ b/src/main/java/com/example/oneul/model/Post.java
@@ -0,0 +1,23 @@
+package com.example.oneul.model;
+
+import java.time.LocalDateTime;
+
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.Id;
+
+import org.springframework.data.annotation.CreatedDate;
+
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+@Getter
+@NoArgsConstructor
+@Entity
+public class Post {
+    @Id @GeneratedValue
+    private Long id;
+    @CreatedDate
+    private LocalDateTime createdAt;
+    private String content;
+}
diff --git a/src/main/java/com/example/oneul/model/User.java b/src/main/java/com/example/oneul/model/User.java
deleted file mode 100644
index 667c377..0000000
--- a/src/main/java/com/example/oneul/model/User.java
+++ /dev/null
@@ -1,33 +0,0 @@
-package com.example.oneul.model;
-
-import java.time.LocalDate;
-
-import javax.persistence.Entity;
-import javax.persistence.GeneratedValue;
-import javax.persistence.GenerationType;
-import javax.persistence.Id;
-
-@Entity
-public class User {
-    @Id @GeneratedValue(strategy = GenerationType.AUTO)
-    private Long id;
-    private String username;
-    private String password;
-    private LocalDate createdAt;
-    
-    public Long getId(){
-        return this.id;
-    }
-
-    public String getUsername(){
-        return this.username;
-    }
-
-    public String getPassword(){
-        return this.password;
-    }
-
-    public LocalDate getCreatedAt(){
-        return this.createdAt;
-    }
-}
diff --git a/src/main/java/com/example/oneul/model/UserEntity.java b/src/main/java/com/example/oneul/model/UserEntity.java
new file mode 100644
index 0000000..143beaa
--- /dev/null
+++ b/src/main/java/com/example/oneul/model/UserEntity.java
@@ -0,0 +1,88 @@
+package com.example.oneul.model;
+
+import java.time.LocalDateTime;
+
+import javax.persistence.Column;
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.Id;
+
+import org.springframework.data.annotation.CreatedDate;
+
+@Entity
+public class UserEntity {
+    @Id @GeneratedValue
+    private Long id;
+    @Column(nullable = false)
+    private String username;
+    @Column(nullable = false)
+    private String password;
+    @CreatedDate
+    private LocalDateTime createdAt;
+
+    public Long getId(){
+        return this.id;
+    }
+
+    public String getUsername(){
+        return this.username;
+    }
+
+    public String getPassword(){
+        return this.password;
+    }
+
+    public LocalDateTime getCreatedAt(){
+        return this.createdAt;
+    }
+
+    public UserEntity(Long id, String username, String password, LocalDateTime createdAt){
+        this.id = id;
+        this.username = username;
+        this.password = password;
+        this.createdAt = createdAt;
+    }
+
+    @Override
+    public String toString(){
+        return "userEntity["
+            + "id: " + this.id
+            + ", username: " + this.username
+            + ", createdAt: " + this.createdAt
+            + "]";
+    }
+    public static class Builder {
+        private Long id;
+        private String username;
+        private String password;
+        private LocalDateTime createdAt;
+
+        public UserEntity build() {
+            return new UserEntity(
+                id, 
+                username, 
+                password, 
+                createdAt);
+        }
+
+        public Builder id(Long id){
+            this.id = id;
+            return this;
+        }
+
+        public Builder username(String username){
+            this.username = username;
+            return this;
+        }
+
+        public Builder password(String password){
+            this.password = password;
+            return this;
+        }
+
+        public Builder createdAt(LocalDateTime createdAt){
+            this.createdAt = createdAt;
+            return this;
+        }
+    }
+}