Abstract:Implantation is the most important scientific topic in the research field of reproductive biology and one of the key weak steps of controlling fertility and infertility. Implantation processes are involved in multiple molocular interactions secreted by the uterus,corpus luteum and the embryo and undergo extensive tissue remodeling,angiogenesis and apoptosis in the implantation site. Supported by WHO/Rockefeller Foundation and CONRAD/CICCR,Six Joint International Implantation Research Centers and several research groups have been established Since 1999. It is the goal of these Centers to develop a safe,stable,efficacious and non steroidal anti implantation contraceptive agent for woman use.