Objective To explore therapeutic effect of dipeptidyl peptidase IV inhibitor on type 2 diabetes mellitus with nonalcoholic fatty liver disease. Methods 120 patients suffering type 2 diabetes mellitus with nonal-coholic fatty liver disease from October 2014 to March 2016 in our hospital were randomly divided into two groups:treatment group and control group. Both groups were given type 2 diabetes conventional treatment ,and the treat-ment group was given dipeptidyl peptidase IV inhibitor in addition. Height,weight,waist circumference,hip cir-cumference were measured. Lipid metabolism and,function index,FPG,2 h PG,HbA1c,Ins,C peptide were detected. HOMA-IR was calculated. Results The total effective rate of clinical treatment of fatty liver in the treat-ment group(88.3%)was higher than the control group(78.3%). The difference was statistically significant. FPG , 2hPG,HbA1c,HOMA-IR,LDL-C,TC,TG,AST,ALT andγ-GT in the treatment group were lower than the con-trol group. The difference was also statistically significant. Conclusion The efficacy of sitagliptin in the treatment of type 2 diabetes with nonalcoholic fatty liver was significant. It can also significantly reduce blood glucose and in-sulin resistance. Furthermore ,it has a better effect on the patients with blood glucose control and lipid metabolism regulation.