Abstract: A two-dimensional mesoscale land surface process and atmospheric boundary layer coupled model including a detailed representation of the planetary boundary layer,the soil and the vegetation were presented for studying the influence of the variation of vegetation cover on the soil physical properties and boundary layer climate in the semiarid region of North West China (around 38°N,105°E).Through heat balance equations the soil surface and vegetation surface were merged in a coupled system,in which vegetation was considered as a horizontally uniform layer,soil was divided into 13 layers and the horizontal differences of vegetation cover is a decisive factor to boundary layer climate. It can be used to forecast the radiation,heat and water fluxes in atmosphere.