Abstract: Bile acids，synthesized from cholesterol，are the main components of bile. They take part in fat digestion and absorption while they have cytotoxicity. The fetus liver is able to synthesize bile acids early in intra-uterine life，but poor in metabolism. How to maintain the levels of bile acids in the fetus serum in order to ensure their safety during pregnancy is the main point valued by the obstetrics researchers. In recent years，with the deepening of research in the pathogenesis of ICP and liver related transporters， whether there are some bile acids transporters in human’s plancenta which plays a great role in substances exchange between the fetus and the mother caused researchers’ attention. This review is about the mechanism of bile acids transport in the fetus-mother unit.

Key words: Pregnancy, Cholestasis, Plancenta, Bile acid and salts, Transport