In this work, we consider the population-dispersal dynamics for predator-prey interactions in a two- or three-patchy environment. On each fragmented patch, there is a two-species predator-prey or three-species omnivory ecological system. It is assumed that the predator species of two-species models or the intermediate species and top predator of three-species models are mobile. For the 2-species-2-patch case, we have completely classi_ed all dynamics with respect to all parameters and have showed the local stability of all equilibria. Moreover, some global extinction results are verified analytically. Finally, numerical simulations of 3-species-two-patch and 3-species-3-patch model are performed. The the effect of dispersal rate with respect to the bio-diversity are discussed.