Abstract: Objective The teratogenetic effect of three different dosages of vitamin A in mice was observed in order to ascertain the teratogenetic dose of vigtamin A.Motheds　At the phase of organ formation of embryo,pregnant mice were treated orally with 1.5,2.0,2.7 g/kg vitamin A.At the 18th day of pregnant,embryo were brought out by cesarean section.Out look,bone and internal organs of live embryo were checked for malformation.Normal saline was used as control group.Results　Rate of absorbed embryo and died embryo in all vitamin A treated groups was significantly higher than that in control group(P<0.05).Malformation rate of live embryo outlook in 2.7g/kg group increased obviously,malformation rate of bone in all vitamin A treated groups increased significantly compared with control group(P<0.05).No internal organ malformation was observed.Conclusion　The proper dosage of vitamin A,as a positive control in teratogenetic test,should be 2g/kg.