Abstract: Aiming at quick transmission and display of product model in collaborative design,a new method of progressive viewing and manipulation is proposed.A wireframe model is first presented,then a VRML model gives the more comprehensive view of the assembled components.Points,lines and facets of 3D model are stored in hierarchical levels so that the model is progressively refined and can be manipulated concurrently.The effects of low transmission rate and display speed caused by the limited bandwidth are improved and the response of operating model interactively is accelerated.