The mammary gland is an important organ for mammals to feed the offspring. It provides sufficient nutrients to the offspring by secreting milk. The healthy development of the mammary gland is of great significance to lactation and the survival rate of the offspring. The mammary gland develops through different stages, including embryonic period, puberty, pregnancy, lactation and regression period. The mammary gland is a highly dynamic organ. At different developmental stages, its morphology will undergo significant changes and the cells undergo extensive changes. Adipose tissue is an important part of the mammary gland. In the process of mammary gland development and circulatory remodeling, adipose tissue exhibits regular morphological and functional changes. The dynamic change of mammary gland adipose tissue is a significant feature of mammary gland circulatory development and reconstruction,and it is mainly manifested as changes in morphology and quantity. For example, adolescent mammary gland accounts for more adipocytes,the ratio of pregnancy and lactation decreases, and the ratio of degenerative phase increases, and this process will be repeated in different reproductive cycles. Studies have confirmed that adipose tissue can secrete special physiological factors to regulate the function of epithelial cells and the development of mammary glands, and has the potential to convert with epithelial cells. It is one of the indispensable cellular components in the development cycle of mammary glands. In addition, the abnormal development of adipose tissue also affects the development of epithelial cells and the function of secreting milk. However, it is still unclear how mammary gland adipocyte change in different periods, what is the mechanism, and what functions they play in mammary gland development. In addition, the research on mammary adipose tissue mainly focuses on mice, and there are few researches on other animals, which makes the research on mammary adipose tissue lack species integrity. In summary, this review synthesizes the relevant progress of mammary gland adipose tissue in recent years, and provides basic data for the follow-up study of the mechanism of adipose tissue regulating mammary gland development.