According to the
double-cross mating design and using principles of Cockerham's general genetic model, a genetic model with
additive, dominance and epistatic effects (ADAA model) was proposed for the analysis of agronomic traits.Components of
genetic effects were derived for different generations. Monte Carlo simulation was conducted for analyzing the ADAA model and its reduced AD model by using different generations. It was indicated that genetic variance components could be estimated without bias by MINQUE(l) method and genetic effects could be predicted effectively by AUP method, at least three generations (including parent F1 of single cross and F, of double-cross) were necessary for analyzing the ADAA model and only two generations (including parent and F, of double-cross) were enough for the reduced AD model. When epistatic effects were taken into account a new approach for predicting the heterosis of agronomic abets of double-crosses was given on the basis of unbiased prediction of genotypic merits of parents and their crosses. In addition, genotype ×environment interaction effects and interaction heterosis due to G×E interaction were discussed briefly.