OBJECTIVE：To investigate the effects of Aconitum injection on cartilage oligomeric matrix protein （COMP）， encoded protein by tumor suppressor gene p53（p53 protein）and bone morphogenetic protein 2（BMP-2）in knee osteoarthritis （KOA）model rabbit ，so as to explore the mechanism of the injection in the treatment of KOA. METHODS ：Totally 24 rabbits were randomly divided into blank group ，model group ，Sodium hyaluronate group and Aconitum injection group ，with 6 rabbits in each group. KOA model was established by injecting 2％ papain-0.03 mol/L L-cysteine solution into the articular cavity of rabbits in model group ，sodium hyaluronate group and Aconitum injection group at the 1st，4th and 7th day ，respectively，except the blank group. At the 1st，4th and 7th day after modeling succeeded ，0.1 mL/kg of normal saline ，Sodium hyaluronate injection and Aconitum injection were injected into the articular cavity of rabbits ，respectively. The cartilage tissue of knee joint was taken from above 4 groups，and the contents of COMP and p 53 protein were detected by ELISA. The cartilage morphology of rabbit knee joint was observed by naked eye. The cartilage of the knee joint was collected and stained by HE staining ，and then the histomorphology changes were observed by light microscope ；Mankin scoring was conducted. The two-step method of PV was used to make the immunohistochemical specimens of knee joint cartilage ，and the relative expression of BMP- 2 was detected. RESULTS ：Compared with blank group ，the edge of cartilage was damaged and the cartilage surface was damaged in the model group. The results of histomorphology observation showed that the joint tissue structure was obviously irregular ，the distribution of chondrocytes was disordered with morphological changes ，and the Mankin score was significantly increased （P＜0.05）；the contents of COMP and cancer cells by indirect inhibition of RAD 51-mediated re - . Suppression of ERCC 1 and RAD51 expression through ERK 1/2 inactivation is essen - tial in emodin-mediated cytotoxicity in human non-small 。E-mail： cell lung cancer cells. p53 protein in knee joint fluid were increased significantly ，while the relative expression of BMP- 2 in knee joint tissue decreased significantly （P＜0.05）. Compared with model group ，the appearance ，histomorphology changes of knee joint cartilage in administration groups were improved，Mankin scores were significantly decreased （P＜0.05）；the contents of COMP and p 53 protein in the knee joint fluid were decreased significantly ，and the relative expression of BMP- 2 in the knee joint tissue were increased significantly （P＜0.05），but there was no significant difference between Aconitum group and Sodium hyaluronate group （P＞0.05）. CONCLUSIONS ：Aconitum injection can improve synovitis inflammation ，delay articular cartilage degeneration ， promote cartilage repair and protect joints of KOA model rabbits. The mechanism may be related to inhibiting COMP secretion ， decreasing p 53 protein expression and promoting BMP- 2 release.