diff --git a/trunk/research/players/js/srs.page.js b/trunk/research/players/js/srs.page.js
index 26b3971e1..ffc88cdfa 100755
--- a/trunk/research/players/js/srs.page.js
+++ b/trunk/research/players/js/srs.page.js
@@ -24,7 +24,7 @@ function update_nav() {
 }
 
 // Special extra params, such as auth_key.
-function user_extra_params(query, params) {
+function user_extra_params(query, params, rtc) {
     var queries = params || [];
 
     for (var key in query.user_query) {
@@ -37,6 +37,10 @@ function user_extra_params(query, params) {
             continue;
         }
 
+        if (!rtc && key === 'api_port') {
+            continue;
+        }
+
         if (query[key]) {
             queries.push(key + '=' + query[key]);
         }
@@ -90,6 +94,8 @@ function build_default_flv_url() {
 function build_default_rtc_url(query) {
     // The format for query string to overwrite configs of server.
     console.log('?eip=x.x.x.x to overwrite candidate. 覆盖服务器candidate(外网IP)配置');
+    console.log('?api_port=x to overwrite WebRTC API(1985).');
+    console.log('?schema=http|https to overwrite WebRTC API protocol.');
 
     var server = (!query.server)? window.location.hostname:query.server;
     var vhost = (!query.vhost)? window.location.hostname:query.vhost;
@@ -104,7 +110,7 @@ function build_default_rtc_url(query) {
     if (query.schema && window.location.protocol !== query.schema + ':') {
         queries.push('schema=' + query.schema);
     }
-    queries = user_extra_params(query, queries);
+    queries = user_extra_params(query, queries, true);
 
     var uri = "webrtc://" + server + api + "/" + app + "/" + stream + "?" + queries.join('&');
     while (uri.lastIndexOf("?") === uri.length - 1) {
diff --git a/trunk/research/players/js/srs.sdk.js b/trunk/research/players/js/srs.sdk.js
index af4f48837..5673aa045 100644
--- a/trunk/research/players/js/srs.sdk.js
+++ b/trunk/research/players/js/srs.sdk.js
@@ -210,8 +210,9 @@ function SrsRtcPublisherAsync() {
                     } else if (window.location.href.indexOf('https://') === 0) {
                         ret.port = 443;
                     } else {
+                        // Allow use api_port to specify the WebRTC API port.
                         // For WebRTC, SRS use 1985 as default API port.
-                        ret.port = 1985;
+                        ret.port = ret.user_query.api_port || 1985;
                     }
                 }
             }
diff --git a/trunk/src/core/srs_core_version4.hpp b/trunk/src/core/srs_core_version4.hpp
index c9415a650..0999c7ba2 100644
--- a/trunk/src/core/srs_core_version4.hpp
+++ b/trunk/src/core/srs_core_version4.hpp
@@ -9,6 +9,6 @@
 
 #define VERSION_MAJOR       4
 #define VERSION_MINOR       0
-#define VERSION_REVISION    224
+#define VERSION_REVISION    225
 
 #endif