Objective To explore the role of C1q/TNF-related protein 3 (CTRP3) in senescence model of mesenchymal stem cells (MSCs) and explore the mechanism. Methods The senescence model of mouse MSCs was induced by hydrogen peroxide (H₂O₂) treatment, and then identified by CCK8 assay and β-galactosidase staining. After exogenous treatment of CTRP3 was given to the obtained MSCs for 24 h, CCK8 was used to detect cell proliferation, and β-galactosidase staining was employed to measure the senescence. The differentiation capacity of the aging MSCs were measured by differentiation induction assay, and the expression of apoptosis-related proteins were detected by Western blotting. Then, RT-PCR was applied for the expression changes of the senescence-related genes P16, P21 and the anti-aging gene SIRT1. ANOVA or LSD analysis was used for intergroup comparison. Results H₂O₂ inhibited the proliferation activity of MSCs in a concentration-dependent manner. After 200 μmol/L H₂O₂ treatment for 4 h, light microscopy displayed that the 3-dimensional impression of the MSCs disappeared, and the cells presented irregular shape. CCK8 assay results showed that the cell proliferation activity was significantly decreased (P<0.05); while the percentage of β-galactosidase positive cells was obviously elevated. After 24 h of CTRP3 treatment, the proliferation and differentiation capacities of senescent MSCs were increased. Western blotting indicated that CTRP3 significantly reduced the apoptosis of senescent MSCs. RT-PCR analysis showed that CTRP3 up-regulated the MSCs anti-aging gene SIRT1 and down-regulated the expression of aging-related genes P16 and P21 at mRNA level. Conclusion CTRP3 treatment inhibits the apoptosis of senescent MSCs, which might be related with the up-regulation of SIRT1 and down-regulation of P16 and P21.