OBJECTIVE： To study antibacterial activities of meropenem （MPN） combined with cefoperazone sulbactam （SCF） to 3 kinds of multidrug resistance （MDR） Gram-negative bacteria. METHODS： Each 50 strains of MDR-Escherichia coli （MDR-EC）， MDR-Klebsiella pneumoniae （MDR-KPN） and MDR-Acinetobacter baumannii （MDR-AB） were isolated from sputum， blood， urine， ascites or drainage specimens of patients during Jan. to Dec. in 2016 from the affilidated hospital of Taishan medical university. The agar dilution method and board method were used to determine MIC50，MIC90 and MICG of MPN， SCF， MPN+SCF to MDR-EC， MDR-KPN， MDR-AB and calculate fractional inhibitory concentration （FIC）. Drug sensitivity test was conducted by K-B disk method. RESULTS： In terms of the MICG to MDR-EC， MDR-KPN， MDR-AB， MPN alone were respectively 36.82， 82.45， 34.32 μg/mL； SCF alone were respectively 42.14， 112.67， 24.11 μg/mL； MPN combined with SCF were respectively 25.97， 56.64， 11.36 μg/mL. In terms of MICG to MDR-EC， MDR-KPN， MICG showed that MPN+SCF＜MPN＜SCF； in terms of MICG to MDR-AB， MICG showed that MPN+SCF＜SCF＜MPN， with statistical significance （P＜0.05）. The highest of FIC of MPN+SCF to MDR-EC， MDR-KPN and MDR-AB was respectively ＞0-0.5 （78.00％），＞0-0.5（72.00％），＞0.5-1.0 （82.00％）. CONCLUSIONS： MPN combined with SCF can effectively improve antibacterial activities to MDR Gram-negative bacteria as MDR-EC， MDR-KPN， MDR-AB. MPN combined with SCF has synergistic effects.