Based on the cloud scheme of Chinese Academy of Meteorological Sciences (CAMS), a 3D warm cloud model with prognostic variable of concentration of aerosols is developed. Coupled with the observed aerosol data for Beijing, the different aerosol distributions effects on microphysical processes of warm cloud are investigated. The results show the CCN concentrations become higher with increasing the concentration of aerosol whose radius are large than 1.0ìm. The increases of concentration of aerosol in range r<1.0 ìm has minor effects on the CCN and cloud drop concentrations. In general, continental aerosol distributions are no much important effects on cloud water content. The sensitivity simulation shows that the reduction of precipitation due to the increases of concentration of aerosols within range 0.1< r <1.0 ìm, which intend to increase the CCN and decrease the mean droplet size with the negative effects on the onset of microphysical processes of collision coalescence. The presence of giant nuclei (r >1.0 ìm) is only important in the initial stages of cloud evolution. It is shown that the giant nuclei enhance the evolution of precipitation due to the increasing of large cloud drop concentration suppress the onset of collision coalescence in the initial stages of cloud evolution. There are no significant effects of giant nuclei on precipitation in the subsequent stage.