Abstract. In this paper, MM-Model is presented for real-time simulation of 3D deformable objects on both global level and local region. This model consists of a deformable centerline and dynamic surface reconstruction mechanism based on Mass-Spring and Medial-Representation respectively. When a relatively small force is applied on the object the model works in the same way as the traditional Mass-Spring. Otherwise the force is directly transferred to the centerline and the surface is dynamically recreated according to the position of the centerline. This model works more effectively and efficiently than traditional elastic ones on the global level due to the advantages of the Medial-Representation reflecting the internal information and the Mass-Spring reducing the response time. A novel collision detection algorithm based on adaptive spatial hash, a cutting approach and suture method are also articulated. An artificial blood vessel’s deformation effect and surgery processes are ...