Abstract:The general circulation and the evolution characteristics of new gene ration radar echo of the heavy rain on Jul. 7，2006 (simply called as “7.7" r ainstorm) in the western Panzhihua (called Panxi) are analyzed in detail. The res ult shows that before raining, there was a plenty of unstable energy, and a vert ical westerly shear in the atmosphere. Near surface cold air and a shear line o ver the Tibetan Plateau triggered an intensive convection and led to a heavy rai n in a large area. The echo intensity of the super cell storm could reach to 60dBz . Long sustained radar echo was the result of new genesis and merging of the ec ho. During the mature stage of radar echo, significant ascending movement took pl ace within the strong echo area. The height of strong echo over 40dBz could be a s high as 9,000 meters with its top height above 12,000 meters. Meanwhile, the a mount of liquid water in the air column reaches 45kg·m-2and there were r everse wind, small size cyclone and convergence as seen in the velocity chart.