The effects of high hydrostatic pressure (HHP) treatment on oyster qualities,such as shelf-life,total bacterial count,total volatile basic nitrogen (TVB-N) and protein,were investigated experimentally.HHP-treated oysters had longer shelf-life than untreated oysters,the shelf-life was prolonged to more than 8 days.The numbers of total bacterial counts in treated oysters were significantly lower than in untreated oysters.