Objective      To determine the expression of Rab11 and its role in the excessive secretion of syncytiotrophoblast exosome (STBEX) when subjected to hypoxia.       Methods       The cultured BeWo cells were divided into 4 groups

that is

cultured under normoxic condition

under hypoxia (92% N

2

5%CO

2

and 3%O

2

)

under normoxic conditions after fusioned with Forskolin

and under hypoxia after f

usioned with Forskolin. Then the protein concentration of STBEX was measured in the supernatant of every group by BCA protein assay. The protein expression of HIF-1α and Rab11 were examined by Western blotting.       Results      Compared with the fused BeWo cells cultured under normoxic condition

the protein concentration of STBEX was significantly elevated in BeWo fused cells cultured under hypoxia (P0.05). The expression levels of HIF-1α and Rab11 were elevated when subjected to hypoxia (P0.05).       Conclusion       Rab11 may promote the excessive secretion of exosome from syncytiotrophoblasts when subjected to hypoxia.