diff --git a/mqtt/0303-PUBLISH.md b/mqtt/0303-PUBLISH.md
index 698e9b4..f6efebd 100644
--- a/mqtt/0303-PUBLISH.md
+++ b/mqtt/0303-PUBLISH.md
@@ -8,11 +8,42 @@ PUBLISH控制报文是指从客户端向服务端或者服务端向客户端传
 
 ##### 图例 3.10 – PUBLISH报文固定报头
 
-| **Bit** | **7**                | **6** | **5**   | **4**  | **3** | **2** | **1** | **0** |
-|---------|----------------------|-------|---------|--------|-------|-------|-------|-------|
-| byte 1  | MQTT控制报文类型 (3)  |       |         |        | DUP   | QoS-H | QoS-  | RETAIN|
-|         | 0                    | 0     | 1       | 1      |       |       |       |       |
-| byte 2  | 剩余长度             |
+<table style="text-align:center">
+   <tr>
+     <td align="center"><strong>Bit</strong></td>
+     <td align="center"><strong>7</strong></td>
+     <td align="center"><strong>6</strong></td>
+     <td align="center"><strong>5</strong></td>
+     <td align="center"><strong>4</strong></td>
+     <td align="center"><strong>3</strong></td>
+     <td align="center"><strong>2</strong></td>
+     <td align="center"><strong>1</strong></td>
+     <td align="center"><strong>0</strong></td>
+   </tr>
+   <tr>
+     <td>byte 1</td>
+     <td colspan="4" align="center"> MQTT控制报文类型 (3)</td>
+     <td align="center">DUP</td>
+     <td align="center">QoS-H</td>
+     <td align="center">QoS-</td>
+     <td align="center">RETAIN</td>
+   </tr>
+    <tr>
+       <td></td>
+       <td align="center">0</td>
+       <td align="center">0</td>
+       <td align="center">1</td>
+       <td align="center">1</td>
+       <td align="center">X</td>
+       <td align="center">X</td>
+       <td align="center">X</td>
+       <td align="center">X</td>
+     </tr>
+   <tr>
+     <td>byte 2...</td>
+     <td colspan="8" align="center">剩余长度</td>
+   </tr>
+ </table>
 
 #### 重发标志 DUP