To investigate the effect of fire needle acupuncture around the knee on behavior, joint morphology and lysyl oxidase related protein 2 (LOXL2) in cartilage of rats with knee osteoarthritis (Knee osteoarthritis,KOA).Methods:30 healthy male rats were selected and 10 rats were used as control without any treatment.KOA model was established in 20 rats.After the model was established, the rats were randomly divided into two groups.They were treated with common acupuncture and around knee fire needling respectively, once every 3 days for 6 consecutive times.The Leauesne MG score, articular chondrocytes and the levels of transforming growth factor-β 1 (TGF-β 1), tumor necrosis factor-α (TNF-α), matrix metalloproteinase-3 (MMP-3) and LOXL2 in peripheral blood and articular cartilage were observed.Results:After treatment, the local pain stimulation response, gait, joint range of motion and joint swelling of the Leauesne MG scoring in the fire needling group were significantly different from those in the control group and the model group (P<0.05）.The levels of MMP-3, TGF-β 1 and TNF-α in serum and articular cartilage in the fire needling group were significantly lower than those in the model group（P<0.05）, while LOXL2 was significantly higher than that in the model group（P<0.05）.Under electron microscope, the chondrocytes in the fire needling group had regular shape, complete and full nucleus, a small amount of microvilli, abundant endoplasmic reticulum and scattered chromatin.Conclusion:Fire needling around the knee can reduce the injury of K0A articular cartilage, reduce the inflammatory reaction and improve the level of cartilage LOXL2, which may be one of the mechanisms of fire needling in the treatment of KOA.