Abstract: S100P，one member of the S100 calcium binding protein family，has been found highly expressed in various tumor cells，participated in the proliferation，survival，metastasis and invasion of tumor cells，and related to the development，prognosis，and drug resistance of tumors. Recently，it has also been found up-regulated expression in human endometria in the “window of implantation”，and evidence shows that progesterone can boost its expression. These evidences prompt that S100P may play a role in embryo implantation. Endometrial receptivity is a prerequisite for embryo implantation，which is crucial for successful pregnancy. There are many biological processes in embryo implantation similar to that in tumor，such as cell proliferation，apoptosis，adhesion，invasion and angiogenesis. This paper reviews the publications about S100P and its relationship between endometrial receptivity and embryo implantation.

Key words: S100 calcium binding protein P, Endometrium, Embryo implantation, Neoplasms