Objective:To explore the mechanism of zoledronic acid (ZOL) affects osteogenic differentiation and bone formation through the regulation of sirtuin 3 (SIRT3) / P53 expression.Methods:Bone marrow mesenchymal stem cells (BMSCs) were induced to differentiate into osteogenic cells, the expression of SIRT3 in the cells was detected, and the targeting regulation relationship between SIRT3 and P53 was analyzed. The intracellular expressions of SIRT3 and P53 were intervened and ZOL was used to treat the cells. MTT method, Western blot method and kit were used to detect cell viability, osteogenesis-related genes Osteoprotegerin (OPG), runt-related transcription factor 2 (Runx2) expression, alkaline phosphatase (ALP) activity and alizarin red S (ARS) staining, respectively. Ovariectomy (OVX) was used to construct a rat model and explore the effect of ZOL on the progression of osteoporosis (OP) in vivo.Results:ZOL promoted osteogenic differentiation of BMSCs. The expression of SIRT3 was down-regulated in the serum of OP patients (0.78±0.23) compared with that of healthy subjects (1.00±0.26 vs. 0.78±0.23. t=3.85, P<0.001). During the osteogenic differentiation of BMSCs, the expression level of SIRT3 gradually increased with the prolonged induction of osteogenesis. Compared with the p53 protein expression and BMSCs activity in the control group, SIRT3 knockout could increase the expression level of p53 protein (0.59±0.05 vs. 1.01±0.11. t=6.02, P=0.004) but inhibited the activity of BMSCs (100.00±8.41 vs. 51.26±5.59. t=8.36, P=0.001). After ZOL treatment, the inhibitory effect of SIRT3 on cell viability (49.61±5.11 vs. 87.61±7.31. t=7.38, P=0.002) and osteogenesis was relieved, and the level of P53 was inhibited (1.10±0.10 vs. 0.69±0.04. t=6.59, P=0.003). P53 overexpression partially offseted the effects of ZOL on cell viability (84.61±6.52 vs. 66.54±5.47. t=3.68, P=0.021) and osteogenesis. Compared with the sham surgery group, the OVX group showed inhibition of osteogenesis in rats, and ZOL treatment significantly improved osteogenic inhibition. ZOL treatment increased the expression level of SIRT3 protein in bone tissue of OVX rats, but inhibited the expression level of P53. Conclusion:ZOL promoted osteogenic differentiation and bone formation of BMSCs by promoting the ubiquitination and degradation of P53 by SIRT3.