Objective:To investigate the expression of HIF-1 and VEGF and the correlation with pathological score of synovium in adjuvant-induce-arthritis rat knee joint.Methods: Models of adjuvant arthritis(AA)in rats were made successfully, the arthral pathological score was calculated, production of HIF-1α and VEGF protein was assayed by histoimmunchemical staining at different stage after CFA inoculation.Results:The HIF-1α and VEGF concentration in experimental group were higher than that in control group, and there was significant difference (P＜0.01).And correlation between them was significantly(P＜0.01), similar with pathological score of synovium(P＜0.01).Conclusion:HIF-1α and VEGF play important roles in the development and progression of synovium of knee joint in AA rat.The interaction of them promote development and progression of neonatal vascular in synovium.