Abstract: By use of the data of severe local storms in the Pearl River Delta and from Guangzhou's sounding from March to August of 1976-1983,the favorable and unfavorable conditions of the genesis of the storms in the area,which is situated in the tropics,are analysed.And the conditions are compared with those in the extratropics.The conclusions in this paper could be helpful to forecasting and understanding of the storms in the Delta.