Abstract: OBJECTIVE To explore the expressions of interleukin-6 (IL-6), signal transducer and activator of transcription 3 (STAT3) and vascular endothelial growth factor (VEGF) in peripheral blood of diabetic nephropathy patients complicated with nosocomial infection and analyze the significance. METHODS A total of 26 diabetic nephropathy patients who were complicated with nosocomial infection and treated in Xingtai People's Hospital from Nov 2018 to Dec 2019 were assigned as the infection group, meanwhile, 130 diabetic nephropathy patients who were not complicated with nosocomial infection were chosen in a 1:5 ratio and assigned as the no infection group. The clinical specimens were collected from the patients of the infection group, the isolated pathogens were identified, the peripheral blood specimens were extracted from the patients, the levels of serum IL-6, VEGF and the relative expression level of STAT3 mRNA in peripheral blood menonuclear cell(PBMC)was detected, and the efficiencies of the indexes in diagnosis of infection were evaluated by receiver operating characteristic (ROC) curve. RESULTS Totally 33 strains of pathogens were isolated from the submitted specimens of the 26 diabetic nephropathy patients complicated with nosocomial infection; Pseudomonas aeruginosa (24.24%), Staphylococcus aureus (21.21%) and Klebsiella pneumoniae (12.12%) were dominant among the isolated pathogens. The levels of peripheral blood IL-6, VEGF and the relative expression level of STAT3 mRNA in PBMC were higher in the infection group than in the no infection group P＜0.05). ROC curve analysis showed that the areas under curves (AUCs) of IL-6, STAT3 and VEGF were respectively 0.860, 0.775 and 0.728 in diagnosis of the complicated nosocomial infection in the diabetic nephropathy patients, all of them were greater than 0.7, with the predictive efficiencies high. CONCLUSION The expression levels of peripheral blood IL-6, STAT3 and VEGF of the diabetic nephropathy patients complicated with nosocomial infection are elevated, and the efficiencies are high in diagnosis of nosocomial infection.