Use HPLC to study the permeation of ingredients of Shou Tai Wan extract(STW) through placental barriers of Wistar rats at different stages of pregnancy.Methods:The pregnant rats were administered by gavage STW for 5 days at early，middle and late stages of pregnancy. Hepatic portal vein plasma，umbilical veins plasma (at late stage of pregnancy) and embryonic tissues were obtained 1 h，12 h after the final administration of STW. The compounds in biological specimens were identified by HPLC.Results:Among the range of experimental doses，loganin and quercitrin were main compounds in 1 h maternal blood but nothing could examined in 12 h maternal blood，umbilical veins plasma and embryonic tissues at different stages of pregnancy.Conclusion:Under the range of experimental doses，the compounds of STW didn’t permeate through placental barriers of rats. This result showed that the application of STW is safe to embryo in pregnancy.