Abstract: The effects of dietary daidzein on broiler breeders during the late periods of the laying cycle on egg quality, hatching rate and meat quality of the offspring chickens were studied. Broiler breeders feed a basal-diet (n=240, 8 replicates, control) or the basal diet supplemented with 10 mg/kg daidzein (n=240, 8 replicates, daidzein). The laying rate was increased over the whole investigation with the daidzein treatment. Egg quality analysis showed that eggshell thickness and relative weight of eggshell to the whole egg increased 0.03 mm (P < 0.01) and 0.45% (P < 0.05),respectively, in daidzein group. Compared with the control group, egg Haugh unit increased significantly in daidzein group by 4 units(P < 0.05). The hatching rate of fecundated eggs and hatched eggs were decreased by 11.5% and 8.3% after daidzein supplementation, respectively (P < 0.05). Although postnatal growth of the offspring chickens from 1 to 63 days of age was not significantly affected, maternal daidzein supplementation tended to reduce the muscle mass of female chicken. As the breast muscle and leg muscle, the rate of cooking loss24 and drip loss24 were significantly decreased, and the yellowness of breast muscle was significantly increased by daidzein treatment (P < 0.05), while the ratio of myofiber types were not changed. The results suggested that maternal diet supplemented with 10 mg/kg daidzein during late periods of the laying cycle of broiler breeders affect egg quality and meat quality of the offspring chickens.