Abstract: The hereditary of yield-related traits in derivative lines from Indica-Japonica crosses of rice under different breeding stages were studied.The additive-dominance genetic model including genotype/environment interaction was used.The results showed that the traits were ubiquitous not only on the genetic main effects but also the genotype/environment interaction effects.Among them,the days from sowing to heading(DSH)and the 1000-seeds weight(SW)of the first deriving generation were mainly controlled by the additive effects.The remaining seven traits were mainly controlled by the dominant effects.The grain weight per plant(GW),seed setting rate(SS)and SW of the second deriving generation were mainly controlled by the dominant effects.The other six traits were mainly controlled by the additive effects.GW,SS,plant height and panicle length of the fourth deriving generation were mainly controlled by the dominant effects.The other five traits were mainly controlled by the additive effects.The genotype/environment interaction analysis indicated that,beside the traits(i.e.,GW,panicle number per plant(PN)and filled grain number per panicle(FGN)of the first deriving generation,the traits(i.e.,DSH,PN and GN)of the second deriving generation and the traits(PN,GN and FGN)of the fourth deriving generation could not detect any additive/environment interaction effects.The other traits all showed additive/environment interaction effects.In addition,the yield-related traits of the differently derived generations all had the dominant/environment interaction effects.