Summary: A reaction-diffusion system with the Allee effect is built and the dynamic behaviors of the system pattern is analyzed. Firstly, using the linear stability theory, the conditions of existence for Turing instability and Hopf bifurcation are obtained and the stability of Turing patterns is analyzed. Then, by means of analytic and numerical simulations, it is showed that the model exhibits Turing peaks, Turing holes, labyrinths, spiral waves, standing waves and chaotic pattern. Regarding the infectious dose as bifurcation parameter, there are two cases which appear with the infectious dose increase. One case is that Turing peaks, Turing holes and labyrinths occur if diffusion rate is greater than a certain value, which indicates that the spatial distribution of infected individuals changes from sparse to dense, then to sparse. The other case is that spiral waves, standing waves and labyrinths happen if diffusion rate of susceptible individuals is less than the value. If the diffusion rate of susceptible individuals is taken as bifurcation parameter, it is found that stable spiral waves occur whenever the diffusion rate of susceptible individuals is more than or less than the diffusion rate of infectious individuals and the increase of number of defects for spiral waves leads to chaotic patterns with the increase of the diffusion rate of infectious individuals.