Abstract: Cold storage is effective to prolong the storage life of pineapple fruit，but a major problem is that low temperature usually causes blackheart in fruit，adversely affecting the quality and nutritional value of fruit，which seriously affects the pineapple industry development. To investigate the mechanism of hot treatment on alleviating pineapple blackheart，using cultivar‘ Paris’ as material and hot air as treatment method，the effects of hot treatment on physiological and bio-chemical changes of harvested pineapple were studied，results showed that the hot treatment could effectively alleviate the blackheart index of harvested pineapple. The MDA contents of harvested pineapple were decreased by hot treatment，and the H2O2 contents increased. The hot treatment delayed the descending rate of SOD and POD activities during the whole harvested period，meanwhile the CAT activity increased. The POD activity was correlated significantly with blackheart index. These results suggested that hot treatment could increase the antioxidase activities to delay the pineapple senescence，thus reduced the blackheart of pineapple.