Phase transition can generate strong nonlinear effects on the behavior of materials,since the transformed material becomes a new one.On the x-t plane,phase transition wave may be considered as macroscopic phase boundary which divides the material into two parts:the non-transformed region and the transformed region.The phase boundary is not only a mechanical discontinuity,but also a material discontinuity.Lots of works have been carried out on the phase transition behavior under impact loading.However,few focused on the propagation rule of phase boundary.