Tab. gives a summary lightning discharge characteristics underneath different polarity in thunderstorms. By analyzing lightning discharge in 24 thunderstorms, when the surface E
field is positive in thunderstorm, average CG lightning flashes in every thunderstorm are just 9.2 flashes, positive CG lightning flashes are 5 flashes, account for 54%,mean peakcurrent is 42.1kA.But when the surface E field is negative in thunderstorm, average CG lightning flashes in every