Abstract: As impulsive phenomena extensively exist in the nature, introduction of impulsive effect into an ecology model can lead to more accurate and reasonable description of the species and the ecological systems. This paper studies a predator-prey system with impulsive effects and Beddington-DeAngelis functional response. We investigate the existence of a periodic solution by using the theory of coincidence degree. Sufficient conditions for the existence of periodic solution are obtained.

Key words: Beddington-DeAngelis functional response, impulsive effect, predator-prey system, periodic solution, degree of coincidence