To descry the long -range monitor video in manner of Browser/Server, this paper brings forward a stream-media promulgating system based on the B/S video surveillance, and presents the structure and rationale of its collecting, coding, stream-media promulgating, web server and terminal, then analyzes the promulgating process and transfers hierarchy, finally gives a bandwidth adaptive rate-control model and the realization scheme which is based on the detection of packet losing rate and used to resolve the conflict between the fluctuation of WAN load capability and the requirement of video real -time transmission.