By use of numerical weather prediction products and the analysis method of energy,the process of a torrential rain during August 21 — 23, 1995 over Southern Shandong and Shandong Peninsula is analyzed. It is shown that heavy rain is located in the area with high energy tongue at low levels,quasi-saturation and convective instability. Due to association of the positive vorticity on 500hPa with the warm shear of wind on 850hPa and cyclone center on ground,a stronger ascending motion triggers off convective instability energy a torrental rain is then produced. The moisture in the heavy rain area is from southwesterly current and the moisture in the Shandong Peninsula is from southeast.