??By using “713” digitized radar, the formation, development and dissipation processes of 101 convective clouds have been observed from July to September 2001 in the Jianyang weather radar station. Through analyzing these data, the convective cloud precipitation mechanisms in summer are discussed. The results indicate that initial echoes of 89.2% convective and 77.8% multiple-cell convective clouds appear below the 0℃ level; when the echoes reach the ground, compared to convective cells, the major echoes of obviously more multiple-cell convective clouds would expand to the cold/warm zone. Because the echo intensity, scale, precipitation time of multiple-cell convective clouds are greater than the convective cells, they are key precipitation cloud systems in summer and important to artificial precipitation.