Objective To observe the therapeutic efficacy of atorvastatin in the treatment of non-alcoholic fatty liver disease (NAFLD) in patients with type Ⅱ diabetes mellitus.Methods A total of 118 patients with type Ⅱ diabetes mellitus complicated by NAFLD, who visited the outpatient department of internal medicine or were hospitalized in our hospital from January 2010 to March 2012, were divided randomly into treatment group (n=61) and control group (n=57) .Both groups received liver protection therapy and blood glucose control, and atorvastatin (20 mg/d) was administered as an addition in the treatment group.The clinical symptoms, body mass index (BMI) , blood levels of total cholesterol (TC) , triglyceride (TG) , high-density lipoprotein cholesterol (HDL-C) , low-density lipoprotein cholesterol (LDL-C) , alanine aminotransferase (ALT) , and aspartate aminotransferase (AST) , and liver B-mode ultrasound findings were evaluated before and after 6 months of treatment.The enumeration data were analysed by chi-square test, the indices before and after treatment were compared by t-test.Results After 6 months of treatment, the treatment group had a significantly decreased clinical symptom score (t=21.07, P=0.0000) , significantly decreased blood levels of TC ( (6.80±1.20) vs (5.24±0.67) mmol/L, t=8.87, P=0.000) , LDL-C ( (4.38±0.75) vs (3.45±0.68) mmol/L, t=7.17, P=0.0000) , TG ( (2.14±0.56) vs (1.69±0.34) mmol/L, t=5.36, P=0.0000) , ALT ( (61±11) vs (46±9) U/L, t=8.24, P=0.0000) , and AST ( (53±14) vs (41±12) U/L, t=5.08, P=0.0000) , and increased blood HDL-C level (t=1.95, P>0.05) , but there was no significant change in BMI (t=1.84, P=0.0683) .No significant changes in these indices were found in the control group (P>0.05) .Both groups showed changes in liver density as measured by B-mode ultrasound, but there was no significant difference between them (P>0.05) .No adverse events occurred in either group.Conclusion Atorvastatin can markedly relieve clinical symptoms and lower blood levels of TC, LDL-C, TG, ALT, and AST and is safe and effective in the treatment of NAFLD in patients with type Ⅱ diabetes mellitus.