Objective To discuss whether mild hyperuricemia can lead to kidney damage and the protection of decreased uric acid,through observing that hyperuricemia did damage to glomerulus endothelial function and cell proliferation of vascular smooth muscle in rats. Methods Fifty-four male SD rats were divided into four groups,the control group,model group (Oxonate),allopurinol group and Oxonate+allopurinol group.Rats were administered on a low sodium diet and their systolic blood pressure (SBP) were measured each 10 days.ELISA was used to detect rat plasma markers of endothelial function damage [nitric oxide (NO),type-1 plasminogen activator inhibitor (PAI-1),endothelin 1 (ET-1)] and cell proliferation of vascular smooth muscle[plateletderived growth factor (PDGF),cycloxygenase 2 (COX2),monocyte chemotactic protein-1 (MCP-1)],and the markers of inflammatory reaction[interleukin-18 (IL-18),tumor necrosis factor α(TNF-α)].PDGF and nitric oxide synthase (NOS) levels of rats were detected by immunohistochemical method.Renal tissue pathology of rats was observed. Results Compared to the control group,the plasmic concentration of COX2,ET-1,IL-18,PAI-1,PDGF,TNF-o,MCP-1 increased,and NO decreased significantly in rats of model group (all P＜0.05),expression of NOS significantly reduced and PDGF increased (all P＜0.05).Under light microscope,vascular wall thickening,intimal proliferation and lumen slight stricture without uric acid crystals in renal tissue were found in model group,which were obviously improved by using allopurinol. Conclusion Mild hyperuricemia can do damage to endothelial function of glomerulus and lead to vascular cell proliferation,which can be improved through decreasing uric acid.