For bone initial geometries, the periosteal and endosteal diameters are set, the results show that the periosteal and endosteal diameters can increased significantly after simulation, it is presented that periosteum expands outward and endosteal resorbs after expansion. 对骨外膜与骨内膜的初始直径大小进行设置,最后结果表明在生长期内骨干骨外膜和骨内膜直径明显增大,表现出骨外膜向外扩展和骨内膜扩展后吸收。