Based on the data of intensity fields of 714CD Radar and Doppler velocity fields and rainfall stations net established in villages and towns of Henan Province in 2005 and the data of auto-weather stations of Henan, the heavy rainfall in Henan influenced by the Typhoon “Haitang” is analyzed. The main conclusions are as follows: (1) The appearance of the heavy precipitation echoes is earlier about one hour than the mesoscale rain cluster, but the mesoscale rain cluster weakens and disappears earlier than the radar echoes of the heavy precipitation, and steady radar echoes of heavy precipitation are benefit for the form and development of the mesoscale rain cluster;(2) On the Doppler velocity fields, the existence of mesoscale system makes for the development and maintenance of heavy precipitation radar echoes ;(3)The area, influenced continually by the heavy precipitation radar echoes about 45 dBz, can produce“train effect”and lead to rainstorm even heavy rainstorm process. For the large-scale echoes of precipitation, according to the movement rules of the mesoscale rain cluster in village-town rainfall chart, the mesoscale systems in the Doppler velocity fields, such as the adverse wind area, the convergence region, the strong wind zone(low-level jet),can be analyzed to forecast correctly the heavy rainfall area and issue warning signal of the heavy rain.