Abstract: Based on the obser vation data of the lightning location system(three direction finders are set at Liupan mountain,Peny ang and Pingliang lightning and thunderstorm experiment station respectively),radar,sounding and other weather background at Pingliang lightning and thunders to rmex periment station of Chinese Academy of Science between June and August in 1997,compared their applications in convective weather observation,it is found that cloud to ground lightning is an important index.The correlation coefficient between cloud to ground lightning and the precipitation in convective weatheris so high that cloud to ground lightning can estimate precipitation.The regression equation between the precipitation intensity (R) and the frequency of cloud to ground lightning(F)is R=1.692ln F-0.273,and the co rrelation coefficientris 0.8641.The frequency of cloud to ground lightning is just like the convective available potential energy,it can show the formation and development of the convective system.