Heavy rainfall occurs frequently in Sanming of Fujian Province. Numerical models have played an active role in the improvement of the forecast accuracy of disastrous weather, such as heavy rainfall. An analysis is made of several physical quantities and daily rainfall in May and June from 2004 to 2008. The results indicate that 13 physical parameters, such as vertical velocity, vapor flux, relative humidity etc., have clear correlations with heavy rainfall during the flooding season in Sanming. Through combining these physical parameters together, the heavy rainfall numerical forecasting models for counties of Sanming are built and the verification indicates that the models performed well during the flooding season. The coverage of heavy rainfall forecasting is between 60% to 83% from 2004 to 2008, and that the 24hour forecasting accuracy of is 37.5% in 2009.