The effects of reproductive hormone on mouse embryo sexes were studied with in vitro fertilization (IVF), in vitro culture (IVC) and sex identification. Results showed that it had no adverse effects on embryos cleavage and development after the embryos were incubated with the fertilization media with 17beta-E2, FSH and progesterone respectively at the concentration of this study. Mice embryos sex ratios significantly deviated from 1:1(P < 0.01) and skewed in favor of males at the concentration of 17beta-E2 attained 70 pg/mL and progesterone attained 99 pg/mL in IVF culture media respectively. 0.01-0.04 IU/mL FSH had no effects on the mouse embryo sexes.