Abstract: In order to further investigate the physiological and biochemical mechanism of flue-cured tobacco tips harvested and cured with stalk, the contents of pigment and malondialdehyde (MDA) and the activities of amylase, polyphenol oxidase (PPO), superoxide dismutase (SOD) and peroxidase (POD) of DJ (Treatmenmt 1, tips harvested and cured with stalk) and WJ (Treatment 2, tips harvested and cured without stalk) were studied.The results indicated that:1) the degradation of chlorophyll in DJ was faster than that in WJ at earlier yellowing stage (12-24h) while the content of chlorophyll in DJ was basically the same as that in WJ at the end of color-fixing stage;2) the ratio of carotenoid to chlorophyll in DJ and WJ changed basically with the same trend, however, more carotenoid was degraded in DJ;3) the change of activity of amylase in DJ was obviously different from that in WJ, the activity of PPO in DJ was lower than that in WJ on the whole, while the activity of SOD in DJ higher than that inWJ;the activity of POD and the content of MDA in DJ were lower than that in WJ.Taking all three results into account, the physiological and biochemical changes in DJ are beneficial to the quality of cured tips.