Abstract: The changes of physiological reaction were studied in cineraira(Senecio cruentus) leaves which grow about three months suffering from temperature changes from 6?℃ to 1?℃.The results showed that the contents of chlorophyll,relative plasmalemma permeability(RPP),the activity of superoxide dismutase(SOD),the contents of malondialdehyde(MDA) and soluble sugar changed significantly.The content of chlorophyll in the leaves of cineraria decreased with the fall of the temperature and the length of the time.However,under slight stress the significance of the declining tendency of cineraria is less distinctive.RPP in leaves increased obviously.At 6?℃,the activity of SOD in leaves rised at the beginning,then droped with the extension of time,eventually remained stable at the same level as those in the comparison group.Under 3?℃ and 1?℃,the activity of SOD in leaves decreased.The contents of MDA and soluble sugar in leaves increased continuously.