diff --git a/trunk/src/app/srs_app_hls.cpp b/trunk/src/app/srs_app_hls.cpp
index 0e72fa464..41d22b1df 100644
--- a/trunk/src/app/srs_app_hls.cpp
+++ b/trunk/src/app/srs_app_hls.cpp
@@ -475,6 +475,7 @@ SrsHlsSegment::SrsHlsSegment()
     sequence_no = 0;
     muxer = new SrsTSMuxer();
     segment_start_dts = 0;
+    is_sequence_header = false;
 }
 
 SrsHlsSegment::~SrsHlsSegment()
@@ -589,6 +590,19 @@ int SrsHlsMuxer::segment_open(int64_t segment_start_dts)
     return ret;
 }
 
+int SrsHlsMuxer::on_sequence_header()
+{
+    int ret = ERROR_SUCCESS;
+    
+    srs_assert(current);
+    
+    // set the current segment to sequence header,
+    // when close the segement, it will write a discontinuity to m3u8 file.
+    current->is_sequence_header = true;
+    
+    return ret;
+}
+
 bool SrsHlsMuxer::is_segment_overflow()
 {
     srs_assert(current);
@@ -810,7 +824,7 @@ int SrsHlsMuxer::_refresh_m3u8(int& fd, string m3u8_file)
     }
     // TODO: maybe need to take an around value
     target_duration += 1;
-    char duration[34];
+    char duration[34]; // 23+10+1
     len = snprintf(duration, sizeof(duration), "#EXT-X-TARGETDURATION:%d\n", target_duration);
     if (::write(fd, duration, len) != len) {
         ret = ERROR_HLS_WRITE_FAILED;
@@ -823,15 +837,27 @@ int SrsHlsMuxer::_refresh_m3u8(int& fd, string m3u8_file)
     for (it = segments.begin(); it != segments.end(); ++it) {
         SrsHlsSegment* segment = *it;
         
+        if (segment->is_sequence_header) {
+            // #EXT-X-DISCONTINUITY\n
+            char ext_discon[22]; // 21+1
+            len = snprintf(ext_discon, sizeof(ext_discon), "#EXT-X-DISCONTINUITY\n");
+            if (::write(fd, ext_discon, len) != len) {
+                ret = ERROR_HLS_WRITE_FAILED;
+                srs_error("write m3u8 segment discontinuity failed. ret=%d", ret);
+                return ret;
+            }
+            srs_verbose("write m3u8 segment discontinuity success.");
+        }
+        
         // "#EXTINF:4294967295.208,\n"
-        char ext_info[25];
+        char ext_info[25]; // 14+10+1
         len = snprintf(ext_info, sizeof(ext_info), "#EXTINF:%.3f\n", segment->duration);
         if (::write(fd, ext_info, len) != len) {
             ret = ERROR_HLS_WRITE_FAILED;
-            srs_error("write m3u8 segment failed. ret=%d", ret);
+            srs_error("write m3u8 segment info failed. ret=%d", ret);
             return ret;
         }
-        srs_verbose("write m3u8 segment success.");
+        srs_verbose("write m3u8 segment info success.");
         
         // file name
         std::string filename = segment->uri;
@@ -944,6 +970,17 @@ int SrsHlsCache::on_unpublish(SrsHlsMuxer* muxer)
     
     return ret;
 }
+
+int SrsHlsCache::on_sequence_header(SrsHlsMuxer* muxer)
+{
+    // TODO: support discontinuity for the same stream
+    // currently we reap and insert discontinity when encoder republish,
+    // but actually, event when stream is not republish, the 
+    // sequence header may change, for example,
+    // ffmpeg ingest a external rtmp stream and push to srs,
+    // when the sequence header changed, the stream is not republish.
+    return muxer->on_sequence_header();
+}
     
 int SrsHlsCache::write_audio(SrsCodec* codec, SrsHlsMuxer* muxer, int64_t pts, SrsCodecSample* sample)
 {
@@ -1336,7 +1373,7 @@ int SrsHls::on_audio(SrsSharedPtrMessage* audio)
     
     // ignore sequence header
     if (sample->aac_packet_type == SrsCodecAudioTypeSequenceHeader) {
-        return ret;
+        return hls_cache->on_sequence_header(muxer);
     }
     
     if ((ret = jitter->correct(audio, 0, 0)) != ERROR_SUCCESS) {
@@ -1381,7 +1418,7 @@ int SrsHls::on_video(SrsSharedPtrMessage* video)
     // ignore sequence header
     if (sample->frame_type == SrsCodecVideoAVCFrameKeyFrame
          && sample->avc_packet_type == SrsCodecVideoAVCTypeSequenceHeader) {
-        return ret;
+        return hls_cache->on_sequence_header(muxer);
     }
     
     if ((ret = jitter->correct(video, 0, 0)) != ERROR_SUCCESS) {
diff --git a/trunk/src/app/srs_app_hls.hpp b/trunk/src/app/srs_app_hls.hpp
index 01121c9e5..dd42fcca5 100644
--- a/trunk/src/app/srs_app_hls.hpp
+++ b/trunk/src/app/srs_app_hls.hpp
@@ -116,6 +116,8 @@ public:
     SrsTSMuxer* muxer;
     // current segment start dts for m3u8
     int64_t segment_start_dts;
+    // whether current segement is sequence header.
+    bool is_sequence_header;
     
     SrsHlsSegment();
     virtual ~SrsHlsSegment();
@@ -167,6 +169,7 @@ public:
     *       use 0 for the first segment of HLS.
     */
     virtual int segment_open(int64_t segment_start_dts);
+    virtual int on_sequence_header();
     /**
     * whether video overflow,
     * that is whether the current segment duration >= the segment in config
@@ -233,6 +236,13 @@ public:
     virtual int on_publish(SrsHlsMuxer* muxer, SrsRequest* req, int64_t segment_start_dts);
     virtual int on_unpublish(SrsHlsMuxer* muxer);
     /**
+    * when get sequence header, 
+    * must write a #EXT-X-DISCONTINUITY to m3u8.
+    * @see: hls-m3u8-draft-pantos-http-live-streaming-12.txt
+    * @see: 3.4.11.  EXT-X-DISCONTINUITY
+    */
+    virtual int on_sequence_header(SrsHlsMuxer* muxer);
+    /**
     * write audio to cache, if need to flush, flush to muxer.
     */
     virtual int write_audio(SrsCodec* codec, SrsHlsMuxer* muxer, int64_t pts, SrsCodecSample* sample);
diff --git a/trunk/src/core/srs_core.cpp b/trunk/src/core/srs_core.cpp
index 9d600b6b5..e2450a109 100644
--- a/trunk/src/core/srs_core.cpp
+++ b/trunk/src/core/srs_core.cpp
@@ -41,6 +41,7 @@ void srs_update_system_time_ms()
     
     gettimeofday(&now, NULL);
 
+    // @see: https://github.com/winlinvip/simple-rtmp-server/issues/35
     // we must convert the tv_sec/tv_usec to int64_t.
     _srs_system_time_us_cache = ((int64_t)now.tv_sec) * 1000 * 1000 + (int64_t)now.tv_usec;