Abstract: Cyclosporin A （CsA），one of the most powerful immunosuppressant，has been widely used to prevent organ rejection and treat certain autoimmune diseases. CsA at low concentrations can increase the proliferation and reduce the apoptosis of trophoblast cells，as well as promote the trophoblastic migration and invasion in vitro. The study in vivo has showed that administration with low dose CsA at the early stage of pregnancy can reduce fetal resorption rate and improve the pregnancy outcome in murine abortion-prone CBA/J×DBA/2 matings. These results above suggest that CsA appears to have favorable effect on the biological behaviors of trophoblast cell，and might be used as a unique therapeutics for miscarriage，preeclampsia，and other pregnancy-related diseases caused by trophoblast cell dysfunction.

Key words: Cyclosporine, Trophoblasts, Cell proliferation, Apoptosis, Cell migratior, Cell invasion