Abstract: It is difficult to find an efficient tree modeling method because of its own complexity and wind， rain acting on tree. A tree modeling method was constructed which could indicate the intrinsic structural characteristic， complex forms and the effects by the wind，rain， snow and other natural phenomena. Firstly， static model was constructed， based on which the dynamic model was established in which the effects on the tree by the wind， rain， snow and other natural phenomena were considered. The force was calculated by the momentum theorem based on the dynamic model in the wind. And then the value of rupture limit was compared to the Young’s modulus in order to determine the situation of fracture or sway. Thus， the tree dynamic model could be improved in the nature environment. During the modeling process， it was found that dynamic model with this method can reduce time decay and keep the modeling fidelity.

Key words: expanding two and a half dimensional modeling method, static model, dynamic model, rupture limit, condensation level, raindrop