Abstract: To investigate the effects of heat shock on the heattolerance,the cuttings of chrysanthemum ’Jinba’were treated at 40℃ for 8 hours,and then the changes of electrolytic leakage,content of malondialdehyde level(MDA),soluble protein,proline and activity of superoxide dismutase(SOD) and peroxidase(POD) were measured after high temperature stress with different times(1-4 h).The results showed that the electrolytic leakage and the content of MDA in leaves treated with heat acclimation were lower than those of non-treated,the contents of soluble protein and proline and the activities of SOD and POD kept higher levels compared with those of controls.The results indicated that the heat tolerance of chrysanthemum was improved by heat shock treatment.