Abstract: The incidence of endometrial cancer in China has been rising over the previous decades. Obtaining a better understanding of its causes and risk factors, so as to develop more effective primary preventive measures is the fundamental way to fight this cancer. Indeed the role of breastfeeding has attracted much attention in the primary prevention of some cancers in women as a natural, convenient, and economical method. Although the preventive effect of breastfeeding on breast cancer development is widely recognized, its association with endometrial cancer remains controversial. This article systematically reviews the progress of studies assessing breastfeeding and endometrial cancer risk, in order to clarify future research directions for epidemiologists and policymakers.