Abstract: By comparison of the simulated cumulus convection process of RegCM2 using the Kuo scheme, the Grell scheme and the MFS, it is found that the MFS can simulate the cumulus heating and moistening very well. A series of sensitivity tests shown that the disposable parameters for specifying the conversion from cloud droplet storaindrops, the turbulentent rainment and detrainment rates in updrafts and do wndrafts, and the intensity of the dow ndrafts have different degrees of influence to the cumulus convection. Therefore it is much important for cumulus parameterization scheme to define these parameters as accurately as possible.