This study has examined the fertility rate, the viability and the incidence of heteroploidy of each group of Japanese quails divided by their egg productivity using 1,349 early embryos of the Japanese quails which were selected and bred for the levels of total plasma phosphorus. There were differences in the frequencies of heteroploidy of each egg productivity level, EP3 whose egg productivity was superior yielded more heteroploid embryos than EP1 or EP2.