The mesoscale heavy rain vortex is mainly located on the 800-700 hPa isobaric surface with its center between the southwest and northeast jets and an anticyclonic circulation in both its lower part and the upper troposphere. The center of the vortex is a descending area and its rim an ascending band. It is found that the heavy rain vortex center has an obvious tendency to move toward the unstable area of the disturbanc field.