【Abstract】 Objective To investigate the resistance of clinical isolates of P. aeruginosa from Jan 2011 to Dec 2014, and provide a reference for clinical treatment. Methods Disk diffusion test was used to study the antimicrobial susceptibility. Results During the past four years, 1275 strains of P. aeruginosa were isolated from our hospital, of which 452 strains were isolated from ICU (355%). The strains were mainly isolated from sputum specimens of the respiratory tract (701%). P. aeruginosa isolated from the ICU showed the lowest resistance rate to amikacin (190%), while exhibited the highest resistance rate to cefoperazone (473%). The resistance rates of P.aeruginosa to piperacillintazobactam, cefoperazonesulbactam, ceftazidime, cefepime fluctuated from 210% to 343%, and the resistance rate to imipenem reached up to 363%. P. aeruginosa isolated from the nonICU still had the lowest resistance rate to amikacin (109%), followed by cefoperazonesulbactam, piperacillintazobactam, cefepime, ceftazidime, imipenem, mezlocillin, ciprofloxacin, gentamycin, piperacillin, aztreonam and cefoperazone in turn, careening between 125% and 399%. The resistance rate of P. aeruginosa and the detection rate of multiple drugresistant P.aeruginosa in the ICU were higher than those in the nonICU. The drug resistance of pseudomonas aeruginosa in our hospital to antimicrobial agents was related to the frequency of drug use. Conclusion Monitoring the antibiotic resistance of multiresistant P. aeruginosa isolated from the ICU is still the key point and analyzing the resistance alteration of the P.aeruginosa will help guide the rational use of antimicrobials clinically and reduce the occurrence of bacterial drug resistance.