Abstract: Embryonic implantation in mammalian is the process of fusion between embryo trophoblast and endometrium. A successful implantation requires：endometrium receptivity；a normal and functional embryo at the blastocyst developmental stage；synchronized development and functional coordination of maternal and embryonic tissues. The implantation process is composed of apposition，adhesion and invasion. Recently，new studies revealed that a lot of crucial genes，protein molecules and their related signaling pathways participated in the mammalian embryo implantation，such as CSPG4，EGF，VEGF，and etc. It is beneficial to the diagnosis，treatment and prevention of infertility in future to elucidate those critical genes，molecules and related mechanisms in the process of embryonic implantation.

Key words: Mammals, Embryo implantation, Endometrium, Molecular mechanism