Background Contrast induced acute kidney injury (CI-AKI) is reported to be the third leading cause of in-hospital acute renal failure.Serum uric acid (SUA) could stimulate rennin-angiotensin-aldosterone system,which plays an important role in the pathogenesis of CI-AKI.Hyperuricemia has ever been considered as its risk factor.Recently researches have shown that atorvastatin and probucol could improve CI-AKI separately.However,little is known about the effect of pretreatment with atorvastatin combined with probucol on SUA level in patients who experience coronary angiography (CAG) or percutaneous coronary intervention (PCI).Therefore,in this study,we investigated the effects of different doses of atorvastatin combined with fixed dose of probucol on the level of SUA and its role in improving CI-AKI.