Abstract: Objective：To explore the protection mechanism of Schisandrin B on extravillous trophoblast cell line damage caused by BaP. Methods：After 0.5，1，2 μmol/L Sch B deal with human HTR8-SVneo cells 24 h，added 20 μmol/L Bap 24 h，using MTS measured cells growth. Used JC-1 fluorescent staining to measure the change of mitochondrial membrane potential in each group. Respectively used ELISA to measure the concentration of Bax and cyt-c protein in each group. Respectively used Western blotting to analyse the expression of caspase-9 in each group. Results：①MTS results showed that BaP alone cell OD was 1.187±0.015，0.5，1，2 μmol/L Sch B the role of OD was 1.483±0.022，1.489±0.048 and 1.531±0.240，compared with BaP alone group，the differences were statistically significant（P＜0.05）. ②JC-1 fluorescent staining results showed that BaP alone cell mitochondrial fluorescent intensity was lower and 0.5，1，2 μmol/L Sch B the role of mitochondrial fluorescent intensity was higer. Compared with BaP alone group，the differences were statistically significant（P＜0.05）. ③ ELISA results showed that BaP alone cell the concentration of Bax，cyt-c protein were higher and 0.5，1，2 μmol/L Sch B the role of the concentration of Bax，cyt-c protein were lower，respectively. Compared with BaP alone group，the differences were statistically significant（P＜0.05）. ④Western blotting results showed that BaP alone cell the concentration of caspase-9 protein was higer，and 0.5，1，2 μmol/L Sch B the role of the concentration of caspase-9 protein was lower，respectively. Compared with BaP alone group，the differences were statistically significant（P＜0.05）. Conclusions：Schisandrin B can prevent damage of extravillous trophoblast cell line caused by BaP，whose mechanism may be associated with resistance to mitochondrial pathway.

Key words: Schisandrin B, BaP, Extravillous trophoblast cell, Mitochondria, Cyt-c