Abstract: In distributed multimedia systems,the characteristics of multimedia synchronization is dynamic,and the key medium has the priority in multimedia synchronization.The proposed multimedia synchronization models can not meet these requirements.So a new multimedia dynamic synchronization model,DSPN,based on timed Petri net,has been designed.This model can not only let the distributed multimedia system keep the multimedia synchronization in a more precise and effective manner according to the run time situation of the system,but also allow the user to interact with the presentation of multimedia.