The purpose of this study was to evaluate the effect of modified atmosphere packaging (MAP)with varying O2 concentrations on the quality changes of Pacific white shrimp during cold storage at(4±1)℃ by using the quality indices such as Total viable counts (TVC), TVB-N, pH, firmness,whiteness and sensory evaluation.Results showed that MAP inhibited the microbial growth and the spoilage which was confirmed by the lowered TVC and TVB-N.Among the four MAP groups, shrimp packaged in bags 40%CO2\55%O2\5%N2 showed the lowest level of TVC and TVB-N, and shrimp in40%CO2\5%O2\55%N2 had the best appearance with lighter blackspots during storage.Low O2concentration packaging exhibited the ability to retard melanosis, but weakening the ability to impede the spoilage.Higher O2 concentration with low CO2 concentration packaging inhibit the microbial growth compared to the CK, but improved the melonasis of shrimp and reduced its sensory quality rapidly.