Abstract: According to the difference of bearing structures between railway and highway under the dynamics key properties of the dynamic loading were analyzed by LUSAS FEM. The curves of displacement on the vertical direction and stress versus dynamic time as well as the relationship between eigenvalues and dynamics frequency about the railway and highway were obtained. The hurtful frequency and hurtful dynamic time of dynamic loading were acquired from analytic results. Combined with a in-situ engineering case of a soil-masses slope, located in Shandong province on No.205 national highway, a numerical model under the two dynamic loading was built by using FLAG. Four different loading conditions worked on the unstable mechanism of soil slope were discussed respectively.