A method, an apparatus and a system for operating Quality of Service, QoS, based on stream, are provided. The method may include: delivering a Real-Time Transport Protocol, RTP, data stream feature to a forwarding plane; learning a RTP packet which is delivered by the forwarding plane conforming to the RTP data stream feature; and judging the RTP data stream to be a determined RTP data stream based on the RTP packet learned; identifying and monitoring the determined RTP data stream to obtain control strategy of QoS of the determined RTP data stream; and delivering the control strategy of the QoS of the determined RTP data stream to the forwarding plane so that the forwarding plane manipulates QoS of the determined RTP data stream based on the control strategy of QoS.