A local heavy rain occurred in the southernmountainous region of Yongchang County on July 14, 2006 was analyzed synthetically from several aspects of physical quantities, moisture condition, p recip itation intensity, satellite images and radar features. Results show that the wind shear convergence at the level of 500 hPa ismain factor resulting in thisweather event, and the wind vertical shear p rovides favorable conditions to ascent development of airflow; the convective cells caused by the external flow of vortex cloud system bring on this strong convective p recip itation. Meanwhile, we found that analysis on energy and Showalter index fields could be a good indication to strong convective weather forecast.