Abstract: Branches swaying and breaking with wind are common natural phenomenon.In order to simulate this natural phenomenon fast and realistically,a set of models and methods are presented.First,conditions for leaves falling and branches breaking with strong wind are analyzed,forces applied to the fallen leaves and broken branches are also discussed,and then a moving model is built for leaves falling and branches breaking.Then,effective collision detection algorithms are proposed to solve the collision problems during the falling of leaves and broken branches.Finally,based on these models a visual simulation method which based on physical and statistics for the leaves falling and branches breaking is designed.A visual system for simulating the tree swaying in wind is developed using VC++6.0 and OpenGL.Visual simulation results in different strong wind can be obtained by varying the simulation parameters in the system.The experiments show that our method is effective and can achieve vivid simulation.