diff --git a/ApmBaseDataFlow.proto b/ApmBaseDataFlow.proto
index f272d5a..4267556 100644
--- a/ApmBaseDataFlow.proto
+++ b/ApmBaseDataFlow.proto
@@ -18,8 +18,8 @@ message ApmBaseDataFlow {
     uint32 tuple_dest = 4;
     IPAddress tuple_saddr = 5;
     IPAddress tuple_daddr = 6;
-    bytes src_mac = 7;
-    bytes dst_mac = 8;
+    string src_mac = 7;
+    string dst_mac = 8;
     uint32 vlan_id = 9;
     uint32 start_tm_tv_sec = 10;
     uint32 start_tm_tv_usec = 11;
diff --git a/AppFlow.proto b/AppFlow.proto
index 482d4dd..f66acef 100644
--- a/AppFlow.proto
+++ b/AppFlow.proto
@@ -27,7 +27,7 @@ message AppFlow {
     uint32 output_bytes = 15;
     bytes protocol = 16;	//< protocol
     uint32 app_id = 17;
-    uint32 app_group_id = 18;	//< application group idectification
+    uint32 app_group_id = 18;
     uint32 probe_if = 19;
     uint32 app_style = 20;
     uint32 time_flag = 21;
diff --git a/BussFlowDb.proto b/BussFlowDb.proto
index be7867b..61807e0 100644
--- a/BussFlowDb.proto
+++ b/BussFlowDb.proto
@@ -32,8 +32,8 @@ uint32 request_packets = 17;
 bytes seq_ack = 18;
 uint32 recog_status = 19;
 uint32 probe_if = 20;
-bytes channel = 21;
-bytes dbname = 22;
+string channel = 21;
+string dbname = 22;
 IPAddress request_ip = 23;
 uint32 request_port = 24;
 IPAddress response_ip = 25;