The spatial variability of precipitation distribution is important for land surface hydrology parameterization of GCM. By use of intensified hourly da ta over Huaihe basin during 1998-2003 summer, an analysis is made to study the s patial distribution of precipitation over this area. Results show that the preci pitation spatial distribution is heterogeneous with a close relation to the aver age precipitation intensity and coverage area. Statistical evidence suggests tha t PDF (probability density function) of coverage area and occurrence frequency p robably presented stable mode with properly interval mean rain intensity. The di screte scheme of random precipitation can be used successfully to generate the p recipitation distribution in sub grid.