Abstract: BMPs belong to the transforming growth factor-b superfamily. BMPs have been proved to have extensive bio-logical functions in mammals, including growth regulation, cell proliferation and differentiation. More and more evidence has shown that BMPs play a key role in fertility, especially in folliculogenesis in female mammals. Smad proteins are intra-cellular signaling transduction molecules of BMP family, which can transduce the BMP signal from the cell membrane to the nucleus. In this review, BMPs, BMP/Smad-related signal transduction and the regulation of BMP activity were summa-rized, and the regulatory roles of BMP/Smad signal transduction pathway in folliculogenesis were discussed.