The authors simulated the movement of willow's end branch blown by wind.Clearly this is not natural and real.A tree moves as a whole.Now an algorithm named depth-first numerical integral tree traversal algorithm is given.The algorithm can generate the harmonic and consistent movement of a tree,thus animates the dynamic pose of tree very well.It can also be used to animate other kinds of trees.Moreover,the authors analyzed the obstruction effect of branches and leaves reacting on wind,which including no obstruction,hole,aperture and penetration.Based on the principle of Z-buffer,these effects are processed,and the results are satisfied.