ObjectiveTo study the homology and clinical characteristics of healthcareassociated infection(HAI) due to Pseudomonas aeruginosa (P. aeruginosa) in medical intensive care unit (MICU), so as to guide the clinical prevention of P. aeruginosa transmission and improve therapeutic effect. Methods55 P. aeruginosa strains isolated from 25 patients with HAI in the MICU of a hospital in JanuaryDecember 2014 were performed pulsedfield gel electrophoresis (PFGE) homology analysis and clustering analysis, clinical characteristics, antimicrobial resistance, and transmission characteristics were analyzed.ResultsA total of 25 patients were investigated, with an average age of (69.62±2.13) years, mean hospital stay (49.34±3.18) days; prior to the isolation of P. aeruginosa, 84.00% of patients were treated with broadspectrum antimicrobial agents for >2 weeks, 76.00% of patients had been admitted to MICU, and 52.00% had a ventilatorassisted ventilation. 55 strains of P. aeruginosa were mainly A, F, H, K, N, V, and W, which were the main epidemic strains; patients infected with A, F, H and K strains all had cross in their hospital stay； PFGE profiles of  isolates from 4 patients during different periods showed different strain patterns;  resistance rates of P. aeruginosa to ceftazidime (72.73%), piperacillin/tazobactam (70.91%), and imipenem（70.91%） were all high, resistance rate to amikacin was the  lowest(25.45%). ConclusionManagement of antimicrobial agents should be strengthened in medical institutions, HAI control measures should be strengthened, so as to prevent the transmission of multidrugresistant and extensively drugresistant bacteria in hospitals.