Abstract: As a typical example of ancient timber architectures, the dynamic characteristics of a Sakyamuni tower are investigated numerically by means of finite-element-method(FEM)in this paper. The tower is rebuilt by a delicate finite element model. The mortise and tenon joint in the structure is simulated by a special beam-element group in the model. The stiffness of the element-group joint is determined by modal analyses. Numerical simulation of the seismic response of the tower shows that the second and third floors of the tower must be damaged more seriously than other floors for their severe stresses when acted by seismic loadings. The present analysis of the tower shows the same phenomena. The results provide basis for repairing and reinforcing the ancient timber tower.