Abstract: OBJECTIVE To investigate the effect of bacterial infections on the vascular status of lower extremities in patients with diabetic foot. METHODS A total of 88 patients with diabetic foot and bacterial infections in our hospital from Jun. 2015 to Aug. 2016 were enrolled. Patients were divided into group A (n=24), group B (n=25), group C (n=20) and group D (n=19) according to the classification (A ~ D) of pan-Atlantic society (TASC). The general information and laboratory test indexes of ankle brachial index (ABI), toe brachial index (TBI), and white blood cell count of the four groups of patients were compared. The foot ulcer secretions in patients were collected for bacterial culture and susceptibility testing. RESULTS From group A to group D, the patient's age, course of disease, and the proportion of neutrophils increased gradually (P<0.05), the ratio of ABI and TBI decreased gradually (P<0.05), and the proportion of severe infection and mixed infection increased gradually (P<0.05). A total of 195 strains of pathogenic bacteria were detected in bacterial culture, among which 102 strains were gram-negative bacteria (52.31%), 79 strains of gram-positive bacteria accounting for 40.51%, and 14 strains of fungi accounting for 7.18%. Drug susceptibility results showed that main gram-negative bacteria were more sensitive to amikacin and imipenem, and main gram-positive bacteria were sensitive to dalfopristin andvancomycin. CONCLUSION Lower extremity infection in diabetic patients is associated with vascular lesions. With the development of lower limb vascular disease, the proportion of mixed infection increases, and the degree of infection is more and more serious, so it is recommended to use antimicrobial agents for anti infection treatment.