Abstract: Based on the observation data of regional heavy rain process in Liaoning province from August 27 to August 29,2004 and Doppler radar echo data as well as the conventional synoptic chart data,the applicability of Doppler radar echo in diagnosing heavy rain process was analyzed.A regional heavy rain model for Liaoning province based on Doppler radar echo was developed,and the indicative functions of the products from Doppler radar such as radar reflectivity,radial velocity,were expounded in forecasting short-time convective weather.