Abstract：Model parameters have the important effects on three-dimensional distinct element code(3DEC) modeling of the stress wave propagation and attenuation in jointed rock masses as well as other codes. Two cases are simulated as follows：(1) one case shows one-dimensional sine wave propagation along a finite-length rock bar without joint；and (2) the other case shows one-dimensional sine wave propagation along a finite-length rock bar with a single joint. Three-dimensional numerical experiments are conducted to investigate the effects of element mesh sizes，boundary conditions，joint constitutive models，joint normal stiffness and tension capacity on modeling of wave propagation and attenuation in jointed rock masses by 3DEC. The results are obtained as follows：(1) the element mesh sizes have the important effects on the computing accuracy and time consumption；(2) the viscous boundary condition can eliminate the reflection of stress wave on the free boundary；(3) joint normal stiffness and tension capacity influence the wave propagation，and the transmission coefficient increases with the increasing normal stiffness，while reflection coefficient is dependent on the type of wave. Therefore，the reflection coefficient decreases with the increasing normal stiffness for compression wave；reflection coefficient is independent of normal stiffness for tension wave propagation on the joint without tension capacity；and (4) the continuous yielding model has the similar effect on the coefficients of the transmission and reflection with the constant stiffness model without tension capacity.
