Abstract: A Lotka-Volterra predator-prey system with impulsive invasion between two patches was considered and a mathematical model of population diffusion and prey releasing in periodic state was formulated. Firstly, it was proved that all solutions of the investigated system were positive and uniformly ultimately bounded, the some conditions were obtained to guarantee that the boundary period solution was global asymtotically stable by using some theories of impulsive differential equations, which indicates that the alien species invade successfully and exclude the native species to extinct. Secondly, the coexiting conditions of alien species and native species were given through the discussion of persistence.