Abstract：Objective To investigate the effect of whole body vibration training on biomechanics and Wnt3a protein expression of femur.Methods 48 female SD rats were randomly divided into sham operation group, osteoporosis group and whole body vibration group, 16 in each group.Rats in the osteoporosis group and the whole body vibration group were excised bilateral ovaries to duplicate the osteoporosis model. At the 11th week after operation, the vibration training platform was used to train the whole body vibration group with the amplitude of 2mm, the vibration frequency of 30Hz, each vibration for 20min, five times a week, a total of 12 weeks; rats in the sham operation group and the osteoporosis group were free to move in the cage.After the last intervention, the right femur was taken for 24 hours, the bone morphometric parameters were measured by micro CT, the mechanical parameters of bone structure and materials were measured by three-point bending test, the protein expression of Wnt3a and β - Catenin was measured by Western blotting, and the gene expression of Wnt3a, β - Catenin, cyclin D1 and tcf1 were detected by qRT-PCR.Results Compared with the sham operation group, the bone density, bone volume fraction, bone trabecular quantity and bone trabecular thickness of the osteoporosis group were significantly reduced (P < 0.01), and the bone trabecular space was significantly increased (P < 0.01); compared with the osteoporosis group, the bone density, bone volume fraction, bone trabecular quantity and bone trabecular thickness of the whole body vibration group were significantly increased (P < 0.05), and the bone trabecular space was significantly reduced (P < 0.05).Compared with the sham operation group, the maximum load, elastic load and deflection of the osteoporosis group were significantly reduced (P < 0.05); compared with the osteoporosis group, the maximum load, elastic load and deflection of the whole body vibration group were significantly increased (P < 0.05).Compared with the sham operation group, the maximum stress, elastic stress, maximum strain and elastic modulus in the osteoporosis group decreased significantly (P < 0.05); compared with the osteoporosis group, the elastic stress, maximum strain and elastic modulus in the whole body vibration group increased significantly (P < 0.05).Compared with the sham operation group, Wnt3a, β - Catenin protein and gene expression decreased (P < 0.05), cyclin D1, tcf1 gene expression decreased (P < 0.05); compared with the osteoporosis group, Wnt3a, β - Catenin protein and gene expression increased (P < 0.05), cyclin D1, tcf1 gene expression increased (P < 0.05).Conclusion Whole body vibration training can improve the biomechanical properties of femur and the expression of Wnt3a protein in osteoporotic rats.