Abstract: In order to reveal the regulation of seismic stress wave propagation and the distribution of wave amplitude in jointed rock masses, the wave propagation across persistent joints is simulated firstly, and the results are verified to be consistent with analytical results. Then, the horizontal distribution of transmission coefficient and the effect of joint persistency on wave propagation are researched by simulating seismic stress wave propagation across rock masses with a single non-persistent joint. Moreover, the theoretical analysis is proposed to explain the simulation results. The result shows that the joint segments induce wave attenuation, and rock bridges cause the change of the wave propagation direction. On the other hand, the transmission coefficient of stress wave through non-persistent joints is related to the size of rock bridge （L_r） and the diffraction angle （μ）. When the diffraction angle is small, the transmission coefficient is mainly affected by the size of rock bridge; otherwise, the size of rock bridge and the diffraction angle both affect the propagation of stress wave across non-persistent joints.