The embodiments of the present invention disclose a method, an apparatus and a system for bandwidth control, wherein the method comprises: acquiring and identifying a HTTP request message of a stream media-on-demand service, and forwarding the HTTP request message of the stream media-on-demand service to a media server; receiving a HTTP response message which is returned from the media server and corresponds to the HTTP request message of the stream media-on-demand service; parsing the HTTP response message, and obtaining a playback bit-rate of a stream media file to be transmitted; determining a transmission bandwidth allocated practically for the stream media-on-demand service according to comparison result between the playback bit-rate and a user subscription bandwidth allocated initially for the stream media-on-demand service; and controlling the transmission of the stream media file by adopting the determined transmission bandwidth. As such, in the embodiments of the present invention, the bandwidth control is performed directly on the network element, thereby solving the problem in the prior art that there are more interactions between different network elements and the processing overhead of other network elements is additionally increased while the utilization rate of the network resources is simply and effectively increased.