Abstract:The stability parameter suggested by Yu Shirong was used to analyse the yield stability of the 15 maize hybrids in the medium-late maturing regional test in 1985. The result indicated that the yield of JD118, JD122, HM17, 432 and BC7315×330 was both high and stable. They were adapted to a large range of areas. The corelation and regression analysis of Yu's stability parameter ai and the stability parameter bi suggested by Eberhart and Russell showed that the corelation and negression coefficients between them was 0.9731, and 0.8631 respectively, both of them were significant at 0.01 probability level, proving that Yu's stability parameter ai was as reliable as Eberhart and Russell's stability parameter bi when used in maize hybrids.