By utilizing the ADTD lightning observations, SWAN radar mosaics and CINRAD/SC Doppler radar data of Chengdu, an analysis is made of the characteristics of and relationship between CG (cloud to ground) lightning, strong precipitation and radar echoes of 100 cases in the 12 regional heavy rainfall events in 2009—2011. The results indicate that the frequency of negative flashes changes with time as precipitation intensity does, and there are single and multiple peaks. The higher the frequency of negative CG lighting is, the greater the likelihood of heavy precipitation occurrence is. During 83% of heavy rainfall events, about 6 to 30minutes before the persistent heavy rainfall, the frequencies of negative flashes increase suddenly and continuously, and during 56% of the events, there appears a peak of negative CG lightning. The sudden increasing of CG lightning frequency is a good indicator of heavy rainfall. During 67% of heavy rainfall events, about 6 to 30 minutes after the appearing of precipitation intensity peaks, there appears a peak of negative CG lightning. In the front of strong radar echoes, there occur weak negative flashes, mainly concentrated in the region above 35 dBz and moving along with radar echoes.