diff --git a/trunk/src/core/srs_core_client.cpp b/trunk/src/core/srs_core_client.cpp
index ee10425c1..ec16b95fc 100644
--- a/trunk/src/core/srs_core_client.cpp
+++ b/trunk/src/core/srs_core_client.cpp
@@ -41,6 +41,7 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #define SRS_PULSE_TIMEOUT_MS 100
 #define SRS_SEND_TIMEOUT_MS 5000000L
 #define SRS_RECV_TIMEOUT_MS SRS_SEND_TIMEOUT_MS
+#define SRS_STREAM_BUSY_SLEEP_MS 2000
 
 SrsClient::SrsClient(SrsServer* srs_server, st_netfd_t client_stfd)
 	: SrsConnection(srs_server, client_stfd)
@@ -152,6 +153,16 @@ int SrsClient::do_cycle()
 	SrsSource* source = SrsSource::find(req->get_stream_url());
 	srs_assert(source != NULL);
 	
+	// check publish available.
+	if (type != SrsClientPlay && !source->can_publish()) {
+		ret = ERROR_SYSTEM_STREAM_BUSY;
+		srs_warn("stream %s is already publishing. ret=%d", 
+			req->get_stream_url().c_str(), ret);
+		// to delay request
+		st_usleep(SRS_STREAM_BUSY_SLEEP_MS * 1000);
+		return ret;
+	}
+	
 	bool enabled_cache = true;
 	conf = config->get_gop_cache(req->vhost);
 	if (conf && conf->arg0() == "off") {
diff --git a/trunk/src/core/srs_core_error.hpp b/trunk/src/core/srs_core_error.hpp
index dc421a64d..ed1bef447 100644
--- a/trunk/src/core/srs_core_error.hpp
+++ b/trunk/src/core/srs_core_error.hpp
@@ -78,6 +78,7 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #define ERROR_SYSTEM_CONFIG_BLOCK_START	407
 #define ERROR_SYSTEM_CONFIG_BLOCK_END	408
 #define ERROR_SYSTEM_CONFIG_EOF			409
+#define ERROR_SYSTEM_STREAM_BUSY		410
 
 // see librtmp.
 // failed when open ssl create the dh
diff --git a/trunk/src/core/srs_core_source.cpp b/trunk/src/core/srs_core_source.cpp
index c731aac80..e5d61ec76 100644
--- a/trunk/src/core/srs_core_source.cpp
+++ b/trunk/src/core/srs_core_source.cpp
@@ -268,6 +268,7 @@ SrsSource::SrsSource(std::string _stream_url)
 	enable_gop_cache = true;
 	
 	video_frame_rate = audio_sample_rate = 0;
+	_can_publish = true;
 }
 
 SrsSource::~SrsSource()
@@ -290,6 +291,11 @@ SrsSource::~SrsSource()
 #endif
 }
 
+bool SrsSource::can_publish()
+{
+	return _can_publish;
+}
+
 int SrsSource::on_meta_data(SrsCommonMessage* msg, SrsOnMetaDataPacket* metadata)
 {
 	int ret = ERROR_SUCCESS;
@@ -465,11 +471,13 @@ int SrsSource::on_video(SrsCommonMessage* video)
 #ifdef SRS_HLS
 int SrsSource::on_publish(std::string vhost, std::string app, std::string stream)
 {
+	_can_publish = false;
 	return hls->on_publish(vhost, app, stream);
 }
 #else
 int SrsSource::on_publish(std::string /*vhost*/, std::string /*app*/, std::string /*stream*/)
 {
+	_can_publish = false;
 	return ERROR_SUCCESS;
 }
 #endif
@@ -489,6 +497,8 @@ void SrsSource::on_unpublish()
 	srs_freep(cache_sh_audio);
 	
 	srs_trace("clear cache/metadata/sequence-headers when unpublish.");
+	
+	_can_publish = true;
 }
 
  int SrsSource::create_consumer(SrsConsumer*& consumer)
diff --git a/trunk/src/core/srs_core_source.hpp b/trunk/src/core/srs_core_source.hpp
index 0d6a221eb..2ed1e3fa6 100644
--- a/trunk/src/core/srs_core_source.hpp
+++ b/trunk/src/core/srs_core_source.hpp
@@ -157,6 +157,10 @@ private:
 	* the video frame rate in metadata.
 	*/
 	int video_frame_rate;
+	/**
+	* can publish, true when is not streaming
+	*/
+	bool _can_publish;
 private:
 	SrsSharedPtrMessage* cache_metadata;
 	// the cached video sequence header.
@@ -167,6 +171,7 @@ public:
 	SrsSource(std::string _stream_url);
 	virtual ~SrsSource();
 public:
+	virtual bool can_publish();
 	virtual int on_meta_data(SrsCommonMessage* msg, SrsOnMetaDataPacket* metadata);
 	virtual int on_audio(SrsCommonMessage* audio);
 	virtual int on_video(SrsCommonMessage* video);