To analyze the impact of Bushen Zhuanggu Granules on enterogenous 5-hydroxytryptamine and bone density and mechanism of action.Methods：To compare the enterogenous 5-HT levels of 60 osteoporosis patients pre-and post taking Bushen Zhuanggu Granules. 1)All the patients enrolled were diagnosed as osteoporosis， who were in-patients or out-patients of the General Hospital of Guangzhou Command between May 2011 to December 2012. 2)Measureing enterogenous 5-HT：drew elbow venous blood 3ml between 8-9 am (fasting)， centrifuged at 3000 r/min for 5 minutes at room temperature， and immediately frozen at-80℃.5-HT levels were measured by ELISA. 3)Bone density was measured using GE company's Lunar Prodigy dual energy X ray(DEXA)bone density meter. 4) Biochemical indices of bone：PINP、β-Crosslaps and PTH levels were measured using electrochemiluminescence immunoassay.Results：After 6-months of treatment， the 5-HT levels were reduced by 5.20%， the levels of PINP、β-Crosslaps、PTH were respectively reduced by 12.72%、26.92% and 5.42% (P<0.05); the BMD of lumbar spine L1-L4， femoral neck， wards and troch were increased by 0.96%、1.67%、2.91%、1.44% and 1.29% (P<0.05).Conclusion：The Bushen Zhuanggu Granules can adjust the spleen and kidney functions， decrease the level of enterogenous 5-HT， and increase bone density.