diff --git a/proto/message/v1/message.proto b/proto/message/v1/message.proto
index 199f1f6..834fdbd 100644
--- a/proto/message/v1/message.proto
+++ b/proto/message/v1/message.proto
@@ -89,7 +89,7 @@ message ResponseHead {
 }
 
 message RoutingHead {
-  optional C2C c2_c = 1;
+  optional C2C c2c = 1;
   optional Grp grp = 2;
   optional GrpTmp grp_tmp = 3;
   optional WPATmp wpa_tmp = 6;
@@ -98,7 +98,7 @@ message RoutingHead {
 
 message SsoReadedReport {
   optional SsoReadedReportGroup group = 1;
-  optional SsoReadedReportC2C c2_c = 2;
+  optional SsoReadedReportC2C c2c = 2;
 }
 
 message SsoReadedReportC2C {
diff --git a/proto/message/v2/message.proto b/proto/message/v2/message.proto
index ee4918b..31bfd2a 100644
--- a/proto/message/v2/message.proto
+++ b/proto/message/v2/message.proto
@@ -325,7 +325,7 @@ message CommonMessage {
 message ContentHead {
   optional int32 type = 1;
   optional int32 sub_type = 2;
-  optional int32 c2_c_command = 3;
+  optional int32 c2c_command = 3;
   optional uint32 random = 4;
   optional int32 sequence = 5;
   optional int64 time = 6;
@@ -344,12 +344,12 @@ message RoutingHead {
   optional int32 from_inst_id = 4;
   optional int64 to_uin = 5;
   optional string to_uid = 6;
-  optional CommonC2C common_c2_c = 7;
+  optional CommonC2C common_c2c = 7;
   optional CommonGroup group = 8;
 }
 
 message CommonC2C {
-  optional int32 c2_c_type = 1;
+  optional int32 c2c_type = 1;
   optional int32 service_type = 2;
   optional bytes sig = 3;
   optional int64 from_tiny_id = 4;
@@ -464,7 +464,7 @@ message TmpPtt {
 
 message Trans211TmpMsg {
   optional bytes msg_body = 1;
-  optional uint32 c2_c_cmd = 2;
+  optional uint32 c2c_cmd = 2;
 }
 
 message MsgPush {
@@ -497,7 +497,7 @@ message SendContentHead {
 }
 
 message SendRoutingHead {
-  optional C2C c2_c = 1;
+  optional C2C c2c = 1;
   optional Grp group = 2;
   optional Trans0X211 trans0_x211 = 15;
 }
diff --git a/proto/notify/v1/notify.proto b/proto/notify/v1/notify.proto
index 7407454..fd134c3 100644
--- a/proto/notify/v1/notify.proto
+++ b/proto/notify/v1/notify.proto
@@ -198,7 +198,7 @@ message GeneralGrayTipInfo {
   uint64 busi_type = 1;
   uint64 busi_id = 2;
   uint32 ctrl_flag = 3;
-  uint32 c2_c_type = 4;
+  uint32 c2c_type = 4;
   uint32 service_type = 5;
   uint64 templ_id = 6;
   repeated TemplParam msg_templ_param = 7;
diff --git a/proto/notify/v2/notify.proto b/proto/notify/v2/notify.proto
index 1fb7ce0..f57f7be 100644
--- a/proto/notify/v2/notify.proto
+++ b/proto/notify/v2/notify.proto
@@ -145,7 +145,7 @@ message GeneralGrayTipInfo {
   optional uint64 busi_type = 1;
   optional uint64 busi_id = 2;
   optional uint32 ctrl_flag = 3;
-  optional uint32 c2_c_type = 4;
+  optional uint32 c2c_type = 4;
   optional uint32 service_type = 5;
   optional uint64 templ_id = 6;
   repeated TemplParam msg_templ_param = 7;
diff --git a/proto/service/highway/v1/ntv_2_rich_media_req.proto b/proto/service/highway/v1/ntv_2_rich_media_req.proto
index 51170d5..85729e0 100644
--- a/proto/service/highway/v1/ntv_2_rich_media_req.proto
+++ b/proto/service/highway/v1/ntv_2_rich_media_req.proto
@@ -30,7 +30,7 @@ message SceneInfo {
   uint32 request_type = 101; // 1
   uint32 business_type = 102; // 3
   uint32 scene_type = 200; // 1
-  optional C2CUserInfo c2_c = 201;
+  optional C2CUserInfo c2c = 201;
   optional NTGroupInfo group = 202;
 }
 
diff --git a/proto/service/highway/v2/highway.proto b/proto/service/highway/v2/highway.proto
index 8b65988..8cca02d 100644
--- a/proto/service/highway/v2/highway.proto
+++ b/proto/service/highway/v2/highway.proto
@@ -109,7 +109,7 @@ message SceneInfo {
   optional uint32 request_type = 101;
   optional uint32 business_type = 102;
   optional uint32 scene_type = 200;
-  optional C2CUserInfo c2_c = 201;
+  optional C2CUserInfo c2c = 201;
   optional GroupInfo group = 202;
 }
 
diff --git a/proto/system/v2/system.proto b/proto/system/v2/system.proto
index b461cbc..642d837 100644
--- a/proto/system/v2/system.proto
+++ b/proto/system/v2/system.proto
@@ -101,13 +101,13 @@ message OnlineDevice {
 }
 
 message SsoC2CMsgCookie {
-  optional uint64 c2_c_last_msg_time = 1;
+  optional uint64 c2c_last_msg_time = 1;
 }
 
 message SsoC2CSyncInfo {
-  optional SsoC2CMsgCookie c2_c_msg_cookie = 1;
-  optional uint64 c2_c_last_msg_time = 2;
-  optional SsoC2CMsgCookie last_c2_c_msg_cookie = 3;
+  optional SsoC2CMsgCookie c2c_msg_cookie = 1;
+  optional uint64 c2c_last_msg_time = 2;
+  optional SsoC2CMsgCookie last_c2c_msg_cookie = 3;
 }
 
 message DeviceInfo {
@@ -153,7 +153,7 @@ message SsoInfoSyncRequest {
   optional uint32 req_random = 2;
   optional uint32 cur_active_status = 4;
   optional uint64 group_last_msg_time = 5;
-  optional SsoC2CSyncInfo c2_c_sync_info = 6;
+  optional SsoC2CSyncInfo c2c_sync_info = 6;
   optional NormalConfig normal_config = 8;
   optional RegisterInfo register_info = 9;
   map<uint32, uint32> unknown = 10;