Abstract: To transmit the RTP-based audio/video stream as soon as possible so as to enable the sending terminal to get an optimal transmission rate is a problem to be solved urgently. An algorithm for optimal transmission rate that can be matched rapidly is therefore proposed for continuous medium stream. The algorithm improves the transmitting time for the next RTCP RR packet, which is required to compute in RTCP(real-time transport control protocol), thus making the sending terminal search quickly the current situation of network through RTCP information feedback and readjust timely its transmission rate to lower its influence on the stability of multimedia transmission. Simulation meets the require of real-time requirement.