Evolution takes place in an ecological setting that typically involves interactions with other organism. Predator-prey interactions are ubiquitous in nature. Such interactions have motivated various theoretical models of phenotypic coevolution in prey-predator communities. One considered the ecological model was the Dubis predator-prey model without Alee effect. However, sometimes the prey population may have a decrease in per capita growth rate at low-density populations. In other word that is Allee effect results in the existence of a threshold density below which the population goes extinct. At low density, fecundity may decrease while mortality may increase because of a range of factors including difficulties in finding mates, social dysfunction and inbreeding depression. These demographic changes lead to negative population growth rates and ultimately push the population extinction. Many studies have demonstrated the potential importance of Allee effects for dynamics of small population, range expansion, community composition and biological invasion. It is widely accepted that Allee effects may increase the extinction risk of low density populations. Evolution suicide is likely outcome of the process^[4]. Therefore, it is important to study the coevolution of the phenotypes of predator and prey population subjected to Allee effects. Based on the system of Dubis, we formulate a Predator-prey model which the prey population has Allee effect. For the reason of Allee effect, the prey population will become extinct. Meanwhile we use Matlab made an analog on predator-prey system and get a conclusion on the influence of Allee effect. The system without Allee Effect is too sublimate to apply to the actual life and compare to the system without Allee effect, the system with Allee effect shortens the time of reaching stabilization. By simulating the phase field, we can see the system with Allee effect has very obvious differences than the system without Allee effect. The figure of the system with Allee effect likes a round but the figure of the system without Allee effect gets close to fanshaped. At the same time, the curve has fluctuated on the later, so the densities of predator and prey rise and fall. Such that we can get some enlightenment protecting biological environment.Our study suggests that Allee effect has unstabilizing effect on population dynamics. Therefore, Allee effect has a great influence on endangered species and the research strong theoretical demonstrations on making decisions to protect the engendered population by the authority.