Abstract: The proliferation,development and maturation of ovarian germ cells are regulated by multiple hormones,among which gonadotropins play a key role.In this study a germ-somatic cell coculture model of 18-day-old chicken embryo ovarian cells was established to evaluate effects of follicle-stimulating hormone (FSH) and 17β-estradiol (E2) alone or in combination on germ cell proliferation.Results showed that FSH (0.25-1 IU/mL) and E2(10-1000 ng/mL) both showed an notable increment in germ cells number after 48 h treatment.Furthermore,FSH manifested a synergistic effect with E2 in stimulating germ cell proliferation.These results indicated that FSH might interact with estrogen to promote embryonic ovarian germ cell proliferation.FSH might exert its action by stimulating the synthesis of estrogen or expression of its receptors.