Objective To explore the relationship between serum alanine aminotransferase levels(ALT) and carotid atherosclerosis in benzene exposed workers with nonalcoholic fatty liver disease. Methods 190 Benzene exposed workers with nonalcoholic fatty liver disease were enrolled divided into abnormal ALT group(n=135) and normal ALT group(n=55), the abnormal ALT group was further divided into three groups according to the levels of serum alanine minotransferase (ALT): group1(G1,60 subjects, 40 U/L≤ALT＜60 U/L),group2(G2,40 subjects, 60 U/L≤ALT＜80 U/L),and group3(G3,35 subjects, ALT＞80 U/L),observed if carotid has only thick endomembrane or with plaques. Results The rate of thick endomembrane of carotid and the detection rate of plaque in the abnormal ALT group are higher than those in the normal ALT control group (P<0.05). Compared with the normal ALT control group, no significant different was found in the rate of thick endomembrane of carotid and the detection rate of plaque in G1,but G2 was significantly different(P<0.05),G3 was extremely significantly different(P<0.01). The rate of thick endomembrane of carotid in G1,G2 and G3 increased, among the three groups. There were statistically significant differences in the rate of thick endomembrane of carotid(P<0.05). benzene exposed workers with nonalcoholic fatty liver disease in G3 showed extremely statistical differences on the detection rate of plaque compared to those in G1(P <0.01). Conclusion The increased level of ALT in benzene exposed workers with nonalcoholic fatty liver disease is closely related to carotid atherosclerosis. The benzene exposed workers with nonalcoholic fatty liver disease whose ALT≥60 U/L are apt to carotid atherosclerosis, should accept the necessary precaution and treatment.