Abstract：This paper studied the effects of high temperature stress(45 ℃/36 ℃,day/night)on 4 eggplant(Solanum melongena L.)varieties and the heat injury index,electrolytic leakage,SOD activity,MDA content and the influence exerted by chlorophyll fluorescence of high temperature stress on these varieties.The results showed that heat injury index,electrolytic leakage rate and MDA content in eggplant seedlings increased significantly after high temperature treatment.The rising rate of heat tolerant varieties was lower than those sensitive cultivars.The SOD activity decreased significantly.After 2 days recovery,the SOD activity of heat tolerant eggplants‘06-E417’and‘Zifei No.1’increased by 20.3 % and 20.7 %,respectively than pretreatment,while those of heat sensitive eggplants nearly remained the same.High temperature stress also decreased Fv/Fm，Fv/Fo，ΦPSⅡ，qP，ETR and Fv’/Fm’in eggplant significantly.But the decreasing rate of heat tolerant cultivars is lower than those of heat sensitive cultivars.This indicates that under high temperature stress,the heat tolerant varieties possess higher activity of PSⅡ.
