Abstract:The combined effects of CO2 and cold seawater on the quality of Pacific white shrimp (Penaeus vanmamei) during the storage were investigated. The results showed that the total bacterial count (TBC), Escherichia coli count, H2S producing bacteria count and psychrophilic bacteria count of shrimp preserved in CO2-cold seawater (4℃) were lower than that of control group (samples were not in CO2-cold seawater but cold stroge). As a result, total volatile basic nitrogen (TVB-N), pH value and K value increased more slowly than that of control during storage. Shrimp in CO2-cold seawater was second-grade freshness (TVB-N value of 19.5mg/(100g), K value of 20.3%) after storage eight days comparing to serious spoilage of control. The shear force of shrimp flesh decreased slowly during storage, but there was no obvious difference. Activity of polyphenol-oxidase (PPO) was significantly inhibited by CO2-cold seawater. Meanwhile, melanosis of shrimp and deterioration of sense quality was delayed.