Abstract: A comparision investigation on the mortality of white wax scale insect in relation to rainfall and annual temperature in different years at four counties and one municipality in Guangxi Province has been carried out. The results show that the average annual temperature is a negligible factor on the insect's mortality, but the annual rainfall has been proved to be a causative factor. High mortality usually appears after every heavy rain, and the female insects are more susceptive to it than the males. The upper limit of annual rainfall is about 1552.5mm, under the level of which the insects of both sexes develop normally with low mortality. Under unfavorable conditions a high mortality would follow, the percentages of which varies with the annual rainfall of the year. The results also show that in excessive rainy days the male, though not so susceptible as the female to rain, and yet its wax encrustation will be mildewed and blackened, causing the final death of the insect.