Aim To observe the effects of different atorvastatin doses on contrast induced acute kidney injury （CI-AKI） in patients undergoing coronary angiography （CAG） or percutaneous coronary intervention （PCI）. Methods 106 cases were randomized into 2 groups: one group received 20 mg atorvastatin at night and another group received 40 mg atorvastatin at night, all patients received drug treatment for 3 days before CAG or PCI all patients admitted to hospital within 24 hours completed routine inspections and examinations of heart ultrasound and renal vascular ultrasound and improved renal function in 48 hours after CAG or PCI and the preoperative, and postoperative modification of diet in renal disease （MDRD） method were used to estimate glomerular filtration rate （eGFR） all patients were taken 5 mL middle segment urine three times in the morning before CAG, 2 hours and 48 hours after operation, and neutrophil gelatinase-associated lipocalin （NGAL） was detected with latex enhanced immunoturbidimetric. Results （1）The value of serum creatinine （SCr） （77.44±23.14 mmol/L vs 94.24±36.14 mmol/L, P＝0.014）, uric acid （313.05±110.84 μmol/L vs 354.00±100.66 μmol/L, P＝0.060） and eGFR （92.24±24.74 vs 75.31±31.34, P＝0.009） after CAG or PCI were different between the two groups. （2）The value of 2 h NGAL （33.13±20.44 μg/L vs 50.67±46.95 μg/L, P＝0.013）, 48 h NGAL （27.56±18.64 μg/L vs 58.38±56.81 μg/L, P＝0.001） after CAG or PCI had statistically significant differences between the two groups. （3）The occurrence of CI-AKI was as follows: the 20 mg/d atorvastatin group had 11 cases, the incidence was 20.75%, and the 40 mg/d atorvastatin group had 5 cases, the incidence was 9.43%, there was statistical significance （P＝0.04）. Conclusion Compared with 20 mg/d atorvastatin, 40 mg/d atorvastatin for 3 days before CAG or PCI can reduce the occurrence of CI-AKI.