In this talk, we study an SIS reaction-diffusion model with spatially heterogeneous disease transmission and recovery rates. A basic reproduction number $mathcal{R}_0$ is defined for the model. We first prove that there exists a unique endemic equilibrium if $mathcal{R}_0> 1$. We then consider the global attractivity of the disease-free equilibrium and the endemic equilibrium for two cases. We show that the disease-free equilibrium is globally attractive if $mathcal{R}_0le 1$, while the endemic equilibrium is globally attractive if $mathcal{R}_0> 1$.