Abstract: In this study the genetic analysis of soybean isoflavone contents and its components were carried out based on the NCⅡMating Design in eight soybean varieties. The results showed that the isoflavone contents and its components of soybean seed are quite different among the tested materials, the contents of isoflavone and daidzein are controlled not only by additive effects but also by non-additive effects, while the content of genistin is dominated by non-additive effects, and genistein, glycitin and daidzin are mainly controlled by additive effects. There are significant differences in the contents of isoflavone and its components among the different combinations derived from different parents. The results also indicated that the tested traits of this study are negative heterosis except for the contents of daidzein. Daidzin are positive heterosis based on the data of the GCA and SCA in average heterosis values. It is suggested that soybean variety with high isoflavone contents should be used as one of the parents in breeding program, and it is the best choice that the combinations crossed between two high isoflavone varieties or a high variety and a low one.

Key words: Soybean[Glycine max (L.) Merr.], Isoflavone, Component of isoflavone, Combining ability, Heterosis