Abstract: The local population dynamics with Allee effect and its empirical research are one of the research hotspots in population ecology. Current studies show that the Allee effect caused by the low population density has complex impacts on the time dynamics and the spatial distribution of a single population or metapopulation. However, comprehensive understanding of how the Allee effect will affect the system dynamics in complex ecological relationships is not enough. An ecosystem containing predators with Allee effect and prey with competing relationship is established. And then, the effect of the Allee effect index and the population initial density on the population density and the spatial distribution of each species are analyzed by the ecosystem. The results show that the predators with Allee effect cause the system to produce damped oscillation, against the stability of predation-competition system; increasing the Allee effect threshold prompts the population density of predators to decrease, and the population density of preys to increase; the initial population size of predator has great impacts on the system, and if the initial value is large, the system finally reaches a stable state; however, if the initial value is small, the system is in chaos; the systems with Allee effect are more likely to generate an aggregated distribution pattern in space. These insights can provide necessary theoretical basis for species conservation.

Key words: Allee effects, predation-competition system, stability analysis, numerical simulation, spatial pattern