5 cytoplasmic male sterile lines and 33 restorler lines were used to produce 165 hybrids with North Carolina Ⅱ mating design.These hybrids,together with their parents,were tested for agronomy traits including yield per plant et al.The study showed that F1 generation had significant or extremely significant positive correlation in agronomy traits,combining ability and heterosis.Heterosis utilization was an effect method for agronomy traits improvement of Brassica napus,the effect of heterosis utilization dep...