diff --git a/src/main/java/cn/lunadeer/newbtitle/PlayerTitle.java b/src/main/java/cn/lunadeer/newbtitle/PlayerTitle.java
index dcac2fc..d2abac5 100644
--- a/src/main/java/cn/lunadeer/newbtitle/PlayerTitle.java
+++ b/src/main/java/cn/lunadeer/newbtitle/PlayerTitle.java
@@ -1,13 +1,36 @@
 package cn.lunadeer.newbtitle;
 
+import cn.lunadeer.newbtitle.utils.Database;
+import org.bukkit.entity.Player;
+
+import java.util.UUID;
+
 public class PlayerTitle extends Title {
     private Long _expire_at = -1L;
+    private final UUID _player_uuid;
 
-    public PlayerTitle(Integer id, Long expire_at) {
-        super(id);
+    public PlayerTitle(Integer title_id, UUID player_uuid, Long expire_at) {
+        super(title_id);
+        this._player_uuid = player_uuid;
         this._expire_at = expire_at;
     }
 
+    public static PlayerTitle create(Integer title_id, UUID player_uuid) {
+        String sql = "";
+        sql += "INSERT INTO nt_player_title (title_id, player_uuid, expire_at) ";
+        sql += "VALUES (" + title_id + ", '" + player_uuid.toString() + "', -1) ";
+        sql += "RETURNING id;";
+        java.sql.ResultSet rs = Database.query(sql);
+        try {
+            if (rs != null && rs.next()) {
+                return new PlayerTitle(title_id, player_uuid, -1L);
+            }
+        } catch (Exception e) {
+            cn.lunadeer.newbtitle.utils.XLogger.err("PlayerTitle create failed: " + e.getMessage());
+        }
+        return null;
+    }
+
     public String getExpireAt() {
         if (this._expire_at == -1L) {
             return "永久";
@@ -18,6 +41,10 @@ public class PlayerTitle extends Title {
         }
     }
 
+    public Long getExpireAtTimestamp() {
+        return this._expire_at;
+    }
+
     public Boolean isExpired() {
         if (this._expire_at == -1L) {
             return false;
@@ -25,4 +52,19 @@ public class PlayerTitle extends Title {
             return this._expire_at < System.currentTimeMillis();
         }
     }
+
+    public void setExpireAtTimestamp(Long expire_at) {
+        this._expire_at = expire_at;
+        this.save();
+    }
+
+    private void save() {
+        String sql = "";
+        sql += "UPDATE nt_player_title ";
+        sql += "SET expire_at = " + this._expire_at + ", ";
+        sql += "updated_at = CURRENT_TIMESTAMP ";
+        sql += "WHERE player_uuid = '" + _player_uuid.toString() + "', ";
+        sql += "AND title_id = " + this._id + ";";
+        Database.query(sql);
+    }
 }
diff --git a/src/main/java/cn/lunadeer/newbtitle/SaleTitle.java b/src/main/java/cn/lunadeer/newbtitle/SaleTitle.java
index d3b598e..fc9ed76 100644
--- a/src/main/java/cn/lunadeer/newbtitle/SaleTitle.java
+++ b/src/main/java/cn/lunadeer/newbtitle/SaleTitle.java
@@ -7,8 +7,7 @@ import cn.lunadeer.newbtitle.utils.XLogger;
 import java.sql.ResultSet;
 
 public class SaleTitle extends Title {
-    private final Integer _id;
-    private final Integer _title_id;
+    private Integer _sale_id;
     private Integer _price;
     private Integer _days;
     private Integer _amount;
@@ -16,8 +15,8 @@ public class SaleTitle extends Title {
 
     public SaleTitle(Integer id, Integer title_id, Integer price, Integer days, Integer amount, Long sale_end_at) {
         super(title_id);
-        this._id = id;
-        this._title_id = title_id;
+        this._sale_id = id;
+        this._id = title_id;
         this._price = price;
         this._days = days;
         this._amount = amount;
@@ -94,13 +93,13 @@ public class SaleTitle extends Title {
     private void save() {
         String sql = "";
         sql += "UPDATE nt_title_shop ";
-        sql += "SET title_id = " + this._title_id + ", ";
+        sql += "SET title_id = " + this._id + ", ";
         sql += "price = " + this._price + ", ";
         sql += "days = " + this._days + ", ";
         sql += "amount = " + this._amount + ", ";
         sql += "sale_end_at = " + this._sale_end_at + ", ";
         sql += "updated_at = CURRENT_TIMESTAMP ";
-        sql += "WHERE id = " + this._id + ";";
+        sql += "WHERE id = " + this._sale_id + ";";
 
         Database.query(sql);
     }
diff --git a/src/main/java/cn/lunadeer/newbtitle/XPlayer.java b/src/main/java/cn/lunadeer/newbtitle/XPlayer.java
index 5663e9f..b935d94 100644
--- a/src/main/java/cn/lunadeer/newbtitle/XPlayer.java
+++ b/src/main/java/cn/lunadeer/newbtitle/XPlayer.java
@@ -81,7 +81,7 @@ public class XPlayer {
             while (rs != null && rs.next()) {
                 Integer title_id = rs.getInt("title_id");
                 Long expire_at = rs.getLong("expire_at");
-                PlayerTitle title = new PlayerTitle(title_id, expire_at);
+                PlayerTitle title = new PlayerTitle(title_id, uuid, expire_at);
                 titles.put(title_id, title);
             }
         } catch (Exception e) {
@@ -151,8 +151,31 @@ public class XPlayer {
             Notification.error(_player, "你的余额不足");
             return;
         }
-        // todo 校验是否已有此称号 以及是否已过期
-        // todo 如果已则续费 如果未则购买
+        if (!_titles.containsKey(title.getId())) {
+            _titles.put(title.getId(), PlayerTitle.create(title.getId(), _player.getUniqueId()));
+        }
+        PlayerTitle title_bought = _titles.get(title.getId());
+        if (title_bought.getExpireAtTimestamp() == -1) {
+            Notification.warn(_player, "你已经拥有此称号");
+            return;
+        }
+        set_coin(_coin - title.getPrice());
+        if (title.getDays() == -1) {
+            title_bought.setExpireAtTimestamp(-1L);
+            return;
+        }
+        if (title_bought.isExpired()) {
+            title_bought.setExpireAtTimestamp(System.currentTimeMillis() + title.getDays() * 24 * 60 * 60 * 1000L);
+        } else {
+            title_bought.setExpireAtTimestamp(title_bought.getExpireAtTimestamp() + title.getDays() * 24 * 60 * 60 * 1000L);
+        }
+    }
 
+    public void setTitle(Integer title_id, Long expire_at) {
+        if (!_titles.containsKey(title_id)) {
+            _titles.put(title_id, PlayerTitle.create(title_id, _player.getUniqueId()));
+        }
+        PlayerTitle title = _titles.get(title_id);
+        title.setExpireAtTimestamp(expire_at);
     }
 }