Abstract: OBJECTIVE To explore the pathogens isolated from the patients with chronic lower extremity varicose ulcers（LEVU） and analyze the changes of drug susceptibility. METHODS The clinical data were collected from 123 patients with chronic LEVU who were treated in the Tianjin Hospital from Oct 2017 to Oct 2019 and were retrospectively analyzed. The distribution and drug susceptibility of the pathogens were observed. RESULTS Among the patients with chronic LEVU, 69 were males, 67 were more than 60 years old, 55 had ulcers of right lower extremity, 71 had area of ulcer no less than 10 cm², and 79 were complicated with venous stasis dermatitis; there were 63 patients with the C-reactive protein more than 10 mg/L, 43 patients with the percentage of neutrophils more than 75%, 71 patients with white blood cell counts more than 10×10⁹/L, and 51 patients with procalcitonin more than 10 ng/ml. A total of 146 strains of pathogens were isolated, 86 of which were gram-negative bacteria, 57 were gram-positive bacteria, and 3 were fungi. Among the gram-negative bacteria, there were 29 strains of Pseudomonas aeruginosa and 13 strains of Escherichia coli; Among the gram-positive bacteria, there were 39 strains of Staphylococcus aureus and 12 strains of coagulase-negative Staphylococcus. There were 29 strains of P.aeruginosa that were sensitive to piperacillin and 7 strains that were sensitive to nitrofurantoin; there were 39 strains of S.aureus that were sensitive to vancomycin, linezolid, nitrofurantoin, moxifloxacin and rifampicin, 11 strains that were sensitive to erythromycin, 8 strains that were sensitive to clindamycin, and 0 strain that was sensitive to penicillin; there were 13 strains of Escherichia coli that were sensitive to imipenem, 13 strains that were sensitive to meropenem, 5 strains that were sensitive to piperacillin, and 3 strains that were sensitive to ampicillin. CONCLUSION Chronic LEVU is prevalent in the elderly. The P.aeruginosa, S.aureus and E.coli are dominant among the pathogens causing ulcer infection, and it is necessary to reasonably use antibiotics based on the result of drug susceptibility testing.