Radioactive phosphorus (^(32)P) of single dose up to 40 μc was injected into the egg yolk during the 5th to 15th incubation day. Embryo development, hatchability and chick growth rate up to 150 days old were observed. A single does of 5 to 40 μc of ^(32)P on the 5th to 15th incubation day resulted in the significantly retarded development of the 18 day-old chick embryo as the ^(32)P dosage increased. A significant negative correlation between the ^(32)P dosage on the 12th incubation day and hatchability (r=-0.946) and a linear regression of hatchability loss to ^(32)P dosage (Y=0.372X+17.06) were obtained. The chick growth rate up to 150 days old was decreased significantly as the ^(32)P dosage on the 12th incubation day increased.