Abstract:[Objective] To explore the effect of two Chinese herbal preparations, the Yougui and Buyi on bone metabolism and bone biomechanics in the osteoporosis model of rats. [Methods] A total of 48 Wistar female rats were randomly divided into the sham group, mod- el group, Yougui group and Buyi group, with 12 rats in each group. The rats in the sham group had the fat around the ovaries resected only without ovariectomy, while all those in the remaining groups underwent ovariectomy. Two weeks after surgery, all animals were given intra- gastrically once a day for 12 weeks, the Yougui group and Buyi group received corresponding TCM preparations with dosage of 0.875 ml / 100 g/once time, respectively, whereas the sham group and model group were given 0.9% normal saline in the equal volume. After another 12 weeks, urine within 24 h and blood were collected for bone metabolism assay, and the left femur was taken for bone density and bone bio- mechanics tests. [Results] The model group was significantly higher than the sham group in terms of urine Ca/Cr [(0.6±0.3) vs (0.4± 0.1), P< 0.05] and urine P/Cr [(0.7±0.2) vs (0.5±0.1), P<0.05]. However, the Buyi group proved significantly superior to the Yougui group and model group in terms of Ca/Cr [(0.3±0.1) vs (0.5±0.2) vs (0.4±0.1), P<0.05] and P/Cr [(0.3±0.2) vs (0.6±0.3) vs (0.5± 0.1), P<0.05]. The model group was significantly higher in term of ALP level [(193.4±9.2) U/L vs (128.6±10.4) U/L vs (110.4±9.8) U/L vs (128.9±8.5) U/L, P<0.05], whereas significantly lower in PINP [(186.5±20.3) pg/ml vs (238.9±18.6) pg/ml vs (235.9±18.6) pg/ml vs (207.6±21.1) pg/ml, P<0.05] and BMP-2 [(10.5±0.1) pg/ml vs (15.8±0.2) pg/ml vs (15.7±0.3) pg/ml vs (13.2±0.4) pg/ml, P<0.05] than the sham group, Buyi group and Yougui group. The Buyi group had significantly lower ALP level, while significantly higher PINP and BMP- 2 than the model group and Yougui group (P<0.05), whereas without significant differences with the sham group (P>0.05). Moreover, the Buyi group proved significantly superi- or to the model group and Yougui group in terms of bone mineral density, maximum load and maximum displacement (P<0.05), without sig-nificant differences with the sham group (P>0.05). [Conclusion] In this study, the Buyi preparation of Chinese herbal does presents the ef- fect of anti-osteoporosis.