The heavy rainfall which occurred from 19 to 20 June 2010, was simulated by using WRF model coupled with four land surface processes. The sensitivity of land surface process to the intensity and range of heavy rainfall was analyzed. The results show that the rain bands simulated by four land surface processes coupled with WRF are accordance with the observations, as well as the simulated strong precipitation centers are also in phase with the observations. The lack of land surface scheme leads to the obvious shift of intensity, range and position of heavy rainfall. In addition, the heavy precipitation is associated with areas of large runoff and even larger soil moisture increment. Due to the saturation soil water content, the excess precipitation was assigned to the surface runoff. This is the important reason to the rapid rise of water level. Under wet soil moisture conditions, the enhanced flux of heat from the surface into the boundary layer air favored a relatively large magnitude of PBL height and latent heat flux. This is the key which caused the abnormal precipitation increase of this heavy rainfall event.