In order to support distributed multimedia application description and development, a multimediacommunication mechanism-QoS (quality-of-service)-controlled pipe is presented as a QoS-based platformpoint-to-point multimedia communication abstraction. The formal definitions of QoS-controlled pipe are introduced and its enforcement procedures are discussed in detail. It has been applied to distributed multimedia information-on-demand systems and distributed multimedia systems successfully. Experimental results show that it not only can act as a comprehensiv and integrated of point-to-point multimedia communication mechanism,but also can act as the basis of multimedia group communication mechanism.