Aim To analyze the risk factors of new diagnosed mild or moderate nonalcoholic fatty liver disease (NAFLD), and investigate the vascular damage and endothelial function in patients with NAFLD. Methods 202 new diagnosed patients with mild or moderate NAFLD and 91 healthy controls were selected in the Health Center of the Eighth Hospital of Changsha. Intima-media thickness (IMT) of carotid artery, flow-mediated dilation (FMD) and nitrate-mediated dilation (NMD) in brachial artery were measured by high-resolution ultrasound. The clinical and biochemical characteristics were analyzed between the two groups. Results (1)Compared with the controls, body mass index, waist circumference, hip circumference, waist-hip ratio, systolic blood pressure, diastolic blood pressure, fasting insulin, fasting plasma glucose, low density lipoprotein, total cholesterol, triglycerides, alanine aminotransferase(ALT), aspartate aminotransferase(AST), uric acid, high sensitivity C-reactive protein, HOMA-insulin resistance index were higher, and high density lipoprotein was lower in NAFLD group(P<0.01). (2)Multi-factor logistic regression analysis demonstrated that NAFLD was independently correlated with HOMA-insulin resistance index, high sensitivity C-reactive protein, ALT(OR=2.5,1.3,1.054, P<0.05). (3) Compared with the controls, NAFLD group had higher IMT(0.92(0.0,1.02) vs 0.87(0.4,0.99)), lower FMD (4.7%(2.2%,6.8%) vs 5.2%(2.4%,7.7%)) and NMD (18.5%(12.2%,25.3%) vs 20.5%(12.2%,28.7%)), but this differences had no statistical significance. The differences of IMT, FMD, NMD between the mild and moderate NAFLD groups had also no statistical significance. Bivariate correlation analysis between IMT, FND, NMD and NAFLD had no statistical significance. Conclusion HOMA-insulin resistance index, high sensitivity C-reactive protein, body mass index are independent risk factors for NAFLD. There was no significant differences in vascular damage between patients with mild or moderate NAFLD and healthers, the exact association between vascular damage and NAFLD need further research.