Abstract: OBJECTIVE To observe the effects of pricking blood therapy on local symptoms of the acute gouty arthritis rat model， morphological changes and ultra-structure， and to explore the effective mechanism of pricking blood therapy. METHODS Forty SD rats were randomly divided into control group， model group， drug group and pricking blood group. The acute gouty arthritis model was set by injecting uric acid into the right ankle joint cavity of the rats. The drug group received 120 mg/kg gastric perfusion of ibuprofen; the pricking blood group pricked the right Kunlun points. The diameter of the injected right ankle joint of the forty rats were measured and recorded before modeling， and 6 h， 24 h， and 48 h after the rats were modeled. The morphological changes were observed under light microscope and ultra-structure was under electron microscope. RESULTS For modeling after 24 hours， there were significant statistical differences between pricking blood group and drug group， and between pricking blood group and model group (P<0.05)， while there was no significant statistical difference for modeling after 48 h (P>0.05). From light microscope， sodium urate crystal deposition had been found in model group with dense inflammation infiltration; there were also some sodium urate crystal and inflammation infiltration in drug group; small amount of pink crumby deposition and inflammation infiltration were found in pricking blood group. As shown in electron microscope， for model group， a few of articular cartilage cell membrane was damaged. Inflammation infiltration occurred and cell process endopasmic reticulum expansion turned up with the same occasion for drug group and arrangement of collagen fibers was disordered and dense. For drug group， mitochondria decreased and arrangement of collagen fibers was disordered. For pricking blood group， there was slight disorder in collagen fibers and cell structure was normal. CONCLUSION Pricking blood therapy may reduce the deposition of uric acid sodium in articular cavity， lessen infiltration of the inflammatory cells， and improve the ultra-structure of arthrodial cartilage rapidly and effectively. Compared with conventional therapy， pricking blood therapy has a better effect， and works quickly with less side-effect.