diff --git a/trunk/src/protocol/srs_protocol_sdp.cpp b/trunk/src/protocol/srs_protocol_sdp.cpp
index 5e70b95f8..bb84ee9f9 100644
--- a/trunk/src/protocol/srs_protocol_sdp.cpp
+++ b/trunk/src/protocol/srs_protocol_sdp.cpp
@@ -297,7 +297,7 @@ srs_error_t SrsSSRCGroup::encode(std::ostringstream &os)
     for (int i = 0; i < (int)ssrcs_.size(); i++) {
         os << " " << ssrcs_[i];
     }
-
+    os << kCRLF;
     return err;
 }