Abstract:[Objective] To investigate the effects of paeonol on bone metabolism, involving nuclear faction-kappa B (NF-κB) / matrixmetalloproteinases-9 (MMP-9) signaling pathway, in osteoporotic fracture in rat. [Methods] A total of 52 SD female rats were randomly di-vided into the sham operation (SO) group, model group, calcitriol group and paeonol group, with 13 in each group. Except those in the SOgroup, all the rats underwent bilateral total ovariectomy (OVX), and all animals underwent operation to establish femur fracture with inter-nal fixation 10 weeks later. The sham operation group and model group were respectively given normal saline, while the calcitriol group wasgiven 0.05 μg/kg alfacalcitol, and the paeonol group was given 200 mg/kg paeonol intragastrically once a day for 12 weeks. The BMD andbone microCT were conducted, and serum makers, signaling pathway markers mRNA and protein expression were detected. [Results] At 12weeks after drug administration, the BMD [(0.31±0.06) g/cm2 vs (0.26±0.06) g/cm2 vs (0.25±0.05) g/cm2 vs (0.19±0.04) g/cm2, P<0.001], thetrabecular number (Tb.N) [(5.5±0.6) mm-1 vs (4.7±0.6) mm-1 vs (4.5±0.5) mm-1 vs (3.0±0.4) mm-1, P<0.001] and bone trabecular thickness(Tb.Th) [(78.5±5.4) μm vs (72.3±4.7) μm vs (70.8±5.0) μm vs (46.9±3.8) μm, P<0.001] were ranked from high to low as follows: the SOgroup>the paeonol group>the calcitriol group>the model group with statistically significant differences. In terms of serum detections, thePINP, BGP and ALP were ranked in descending order as the SO group>the paeonol group>the calcitriol group>the model group with statisti-cally significant differences (P<0.05), while the serum TNF-α, IL-6 and IL-8 were in the order from low to high: the SO group<the paeonolgroup<the calcitriol group<the model group with statistically significant differences(P<0.05). In terms of signaling pathway marker detec-tion, both the mRNA and protein expressions of NF-κB p65 and MMP ranked as follows: the SO group<the paeonol group<the calcitriolgroup<the model group, which all were statistically significant (P<0.05). [Conclusion] The paeonol does significantly improve bone mineraldensity, bone microCT measurement and serum bone metabolism markers, while down-regulate the expression of NF-κB/MMP9 signaling pathway markers in OP fractured rats in this study.