diff --git a/Samples/Serial2NetClientTest/Program.cs b/Samples/Serial2NetClientTest/Program.cs
index 39bc2d9..94eae80 100644
--- a/Samples/Serial2NetClientTest/Program.cs
+++ b/Samples/Serial2NetClientTest/Program.cs
@@ -19,7 +19,7 @@ private static void Main(string[] args)
         var host = new A2();
 
         // 配置并打开串口COM1
-        var serial = host.CreateSerial(1, 9600);
+        var serial = host.CreateSerial(Coms.COM1, 9600);
         serial.DataReceived += OnReceiveSerial;
         serial.Open();
 
diff --git a/SmartA2/A2.cs b/SmartA2/A2.cs
index 6ef2041..1fd73f0 100644
--- a/SmartA2/A2.cs
+++ b/SmartA2/A2.cs
@@ -6,6 +6,22 @@
 
 namespace SmartA2;
 
+/// <summary>串口</summary>
+public enum Coms
+{
+    /// <summary>COM1</summary>
+    COM1,
+
+    /// <summary>COM2</summary>
+    COM2,
+
+    /// <summary>COM3</summary>
+    COM3,
+
+    /// <summary>COM4</summary>
+    COM4,
+}
+
 /// <summary>A2硬件工厂</summary>
 public class A2
 {
@@ -39,11 +55,11 @@ public class A2
     /// <param name="baudrate"></param>
     /// <returns></returns>
     /// <exception cref="ArgumentOutOfRangeException"></exception>
-    public SerialPort CreateSerial(Int32 com, Int32 baudrate = 9600)
+    public SerialPort CreateSerial(Coms com, Int32 baudrate = 9600)
     {
-        if (com <= 0 || com > 4) throw new ArgumentOutOfRangeException(nameof(com), $"无效串口COM{com}，支持COM1/COM2/COM3/COM4");
+        if (com < 0 || com > Coms.COM4) throw new ArgumentOutOfRangeException(nameof(com), $"无效串口{com}，支持COM1/COM2/COM3/COM4");
 
-        return new SerialPort(ComNames[com - 1], baudrate);
+        return new SerialPort(ComNames[(Int32)com], baudrate);
     }
 
     /// <summary>创建Modbus</summary>
@@ -51,11 +67,11 @@ public SerialPort CreateSerial(Int32 com, Int32 baudrate = 9600)
     /// <param name="baudrate"></param>
     /// <returns></returns>
     /// <exception cref="ArgumentOutOfRangeException"></exception>
-    public Modbus CreateModbus(Int32 com, Int32 baudrate = 9600)
+    public Modbus CreateModbus(Coms com, Int32 baudrate = 9600)
     {
-        if (com <= 0 || com > 4) throw new ArgumentOutOfRangeException(nameof(com), $"无效串口COM{com}，支持COM1/COM2/COM3/COM4");
+        if (com < 0 || com > Coms.COM4) throw new ArgumentOutOfRangeException(nameof(com), $"无效串口{com}，支持COM1/COM2/COM3/COM4");
 
-        return new ModbusRtu { PortName = ComNames[com - 1], Baudrate = baudrate };
+        return new ModbusRtu { PortName = ComNames[(Int32)com], Baudrate = baudrate };
     }
     #endregion