Abstract: How to construct the soft tissue model with high precision and prompt speed is one of the key issues in virtual surgery.A new method of soft tissue modeling,namely the restricted Delaunay incremental insertion algorithm(RDIIA),based on high quality Delaunay tetrahedralization is proposed.This method put forth a constraining condition that greatly reduces the number of missing boundaries which frequently occur in conventional incremental insertion algorithm.It further recovers the missing boundary during the shape optimization of the newly generated Delaunay tetrahedral model of the soft tissue by local reformation.Experimental results and algorithm analysis show that RDIIA can not only improve the computational performance,but also ensure the computing convergence and model integrity.