Attractivity of Positive Periodic Solution of Multispecies Ecological Delay System
多种群生态时滞系统正周期解的全局吸引性

In this paper, by means of comparison theorem and Liapunov functionals, the authors consider the global attractivity of positive periodic solution of multispecies ecological competition predator system with several periodic delays. Finally, by using persistence theory, the sufficient and necessary conditions of positive periodic solutions are obtained for predator prey delay systems.