Objective:To investigate the protective effects and the possible mechanisms of velvet antler polypeptides (VAP) on microwave radiation-induced injury to the development of secondary follicles in mouse ovaries  Methods:Adult female mice were radiated by microwave with 5 mW/cm,2, intensity for 30 days. After that,the radiated mice were injected intraperitoneally with VAP (1.5 mg·kg-1·d-1,3 mg·kg-1·d-1 and 6 mg·kg-1·d-1) for 30 days. The development of secondary follicles in mouse ovaries was observed. The apoptosis of granulosa cells in secondary follilces was detected by TUNEL assay. The immunohistochemistry technique was used to analyze the expression of anti-apoptosis protein Bcl-2 and active pro-apoptosis protein caspase-3 in granulosa cells from secondary follilces. The content of estrogen in mouse serum was detected by ELISA  Results:Compared with model group,VAP with high concentration significantly improved the development of secondary follicles and histological structure. In high VAP treatment group,the apoptosis of granulosa cells and the expression of active pro-apoptosis protein caspase-3 in granulosa cells from secondary follilces were greatly decreased,while the expression of anti-apoptosis protein Bcl-2 in granulosa cells from secondary follilces and the estrogen level in mouse serum were significantly increased  Conclusion:Thes  Results: suggest that VAP with high concentration can significantly improve the development of impaired secondary follicles induced by microwave radiation in mice; and its mechanism may be associated with reducing the granulosa cell apoptosis in secondary follicles and promoting the synthesis and secretion of estrogen.