Abstract： Objective To explore whether efflux pump inhibitors can improve the sensitivity of ciprofloxacin in drug-resislance Klebsilla pneumoniae. Methods Twenty sensitive strains of Klebsiella pneumoniae were isolated from patients. Ten strains were induced by concentration gradient ciprofloxacin and changed into ciprofloxacin-high resistant Klebsiella pneumoniae. The MICs of ciprofloxacin in the absence or presence of reserpine or carbonyl cyanide m-chlorophenyl hydrazone(CCCP) were detected by agar dilution method. Results After treated with efflux pump inhibitor, the MICs of most induced-resistant bacteria to ciprofloxacin were decreased:6 strains (60%) and 8 strains (80%) in the presence of reserpine and CCCP respectively. The positive efflux pump Klebsiella prveumoniae strains in the presence of reserpine and CCCP were 4(40%) and 6(60%) respectively. Conclusions The high drug-resistance Klebsiella pneumoniae can be artificialy induced with concentration gradient of ciprofloxaein. The efflux pump inhibitors can obviously improve the antibacterial activities of ciprofloxacin in drug-resistance Klebsiella pneumoaiae.