Abstract: By use of June through August daily data of severe local storm and rainfall for the Pearl River Delta stations and sounding data for the GuangZhou station together with the method of correlative contrast,the environmental conditions for the geneses of severe local storm and heavy rain in the circulation of typhoon are statistically diagnosed. Favourable conditions are identified for the two kinds of severe weather with the typhoon influence, which are remarkably different in pressure, wind speed, stratification stability,and geopotential instability at middle-and-lower level.