Abstract: Based on the statistical method, the double channel lightning counter (DB-type) data for hailstorm and thunderstorm, and its stratification correspondly in surmer 1977-1978 and 1985 in the Lanzhou and the Pinliang area of the Gansu province are analysed. The result shows that the numbers of stroke in lightning process are mainly decided by enviroment temperature at the residual instauility of 5℃. The instability have some effect for numbers of stroke, but is not decided for it. Forecasting equation is conducted in this paper with statistical analysis.