In this paper, we present an efficient modeling and rendering realistic trees method based on recursive fractals. Firstly, according to the growth characteristics of poplar trees, we divide the trees model into three parts, trunks, branches and leaves. We provide a multi-branches tree topological structure to organize all the trunks and the branches, and add leaves to leaf nodes of our multi-branches tree structure. Then we define the recursive fractals iterator to generate trunks model and side branches model, and use billboard to simulate the tree leaves. After that, we render the trees. Finally, we implement our method, and model and render different shape trees. The experiments prove that our method is feasible and high performance.