Abstract:This study aimed to characterize the changes in the quality of Lactuca sativa during storage at different temperatures and predict the shelf life.The changes in main quality indices of L.sativa stored at different temperature（3，5，7，25℃）over time were established as functions，and the shelf-life prediction model was further established.The results showed that low temperature storage maintained the edible and commodity value and slowed down the declines in sensory score，vitamin C（VC）content，chlorophyll content and soluble solid content of L.sativa.Moreover，the low temperature storage inhibited stem browning（a*value）and decreased the polyphenol oxidase （PPO）activity，weight loss rate and relative electrical conductivity of L.sativa.Pearson correlation analysis demonstrated strong correlations between other quality indexes except PPO activity and membrane permeability.The changes in VCcontent，chlorophyll content，soluble solid content and sensory score followed the first order reaction kinetic model，and those in weight loss rate and a*value were in accordance with the zero order reaction kinetic model.The established model was verified effective in the prediction of the shelf life of L.sativa.