ObjectiveTo understand antimicrobial resistance and therapeutic efficacy of imipenem/cilastatin and meropenem for treatment of multidrugresistant Pseudomonas aeruginosa (MDRPA) from patients with mechanical ventilation. MethodsFrom January 2010 to December 2015, 78 patients with mechanical ventilation and isolated MDRPA from sputum cultures were selected and divided into  imipenem /cilastatin (n=44) and meropenem(n=34) treatment groups, basic condition, time of  emergence  of drug resistance, and therapeutic efficacy of antimicrobial agents between two groups were compared. ResultsThe basic data of two groups were comparable, before treatment by imipenem/cilastatin and meropenem, resistance rates of Pseudomonas aeruginosa (P. aeruginosa) to quinolones, ceftazidime,  piperacillin, and amikacin were not significantly different (all P>0.05).  After patients received antimicrobial agents for 6 days, difference in antimicrobial resistance between imipenem /cilastatin  and meropenem treatment groups were not significantly different (22.73% vs 8.82%, P>0.05). On the 8th, 10th,and 12th  day of treatment,  resistance rates of imipenem treatment group were 40.91%,77.27%, and 97.73%， respectively, which were all  higher than meropenem treatment group (17.65%,32.35%,44.12%, respectively, all P<0.05）. After the treatment with different antimicrobial agents, the average time for the emergence of resistance in imipenem /cilastatin  and meropenem treatment group were 9.0 days  and 13.5 days respectively.  Therapeutic efficacy between two groups was not significantly different (64.71% vs 74.19%,P=0.41）. ConclusionCompared with meropenem, imipenem/cilastatin shows higher risk for the emergence of drug resistance during therapy of P. aeruginosa infection in patients with mechanical ventilation, there is no significant difference in therapeutic efficacy between two groups of patients after 7 days of treatment.