The Weather Research and Forecasting(WRF) mesoscale numerical prediction model was used to construct mesoscale ensemble forecast from the aspects of model uncertainty.The focus was to compare and analyze the influence on precipitation forecast of mesoscale convection complex(MCC) exerted by the three methods,which were different physical parameterization method,the method of disturbing sensitive parameters in cumulus convection parameterization scheme and the stochastic physical perturbation method.The results showed that all of the three ensemble forecast methods could reflect the uncertainty of MCC precipitation forecast and they performed better than control forecast.Compared to the other two methods,the spatial distribution and intensity of ensemble mean 24-hour accumulated rainfall by stochastic physical perturbation method were closer to the reality.The 24-hour rainfall ETS of stochastic physical perturbation method was better than the other two methods.In terms of root mean square error (RMSE),the stochastic physical perturbation method had smaller RMSEs than the other two methods,while its dispersion was larger than the other two.In all,the stochastic physical perturbation method was superior to the other two methods.