In view of the problem that audio and video are not synchronized, which is caused by factors such as delay, shaking and the change of network condition in transmission, this paper designs a solution for the synchronization of audio and video which adapts to different network. By use of the property of various rates of the codec AMR-WB and H.264,and RTP time stamp and RTCP feedback detection QOS, this synchronization scheme is realized by controlling the codec of audio and video. In the paper, the design process of synchronization algorithm which works in reliable and dynamic network is emphasized, and the feasibility of the scheme is verified through actual test. The results show that this design can guarantee the synchronization of audio and video in different network environment.