By using GMS-5 infrared and water vapour brightness temperature data from Mar. toApr. in 1997 - 1998, the methods of extracting hail weather parameters were developed anddigital remote sensing pictures were obtained in spring in Yunnan. Based on the bivariate probability distribution of infrared and water vapour brightness temperature of hail and no- hail, a criterion distinguishing hail from no-hail was set up. The results show that a precisiondistinguishing hail and no-hail is 94%,the accuracy of hail distinguishing is 30. 8%.