Based on the distribution function of raindrop diameters delivered by Best A.C.,a new theoretical distribution density function for raindrop kinetic energy was developed, which obeyed the Weibull distribution.The study showed that the Weibull distribution could be excellently used in describing rain kinetic energy distribution.Thus, it is not necessary that the total rain kinetic energy was calculated by various empirical formulas,rather,it should be obtained through calculus straightforwardly.