In order to elucidate effect of SNP on the parameters response to drought and relate to drought resistance of cultivars and to supply the new method and theory for drought resistant cultivation in processed potato,we firstly treated droughtresistant potato cv.‘Desiree’ and droughtsensitive potato cv.‘Atlantic’ with 0 (control) and 0.01 mmol·L^-1SNP at bud,and then analyzed plant morphology,the contents of superoxide anion and H₂O₂,as well as activities of antioxidant enzymes under normal water,light waterstress,medium waterstress and heavy waterstress,respectively.The results showed that:(1) SNP treatment could maintain the normal growth of potato under heavy waterstress.(2)The contents of superoxide anion and H₂O₂,as well as activities of CAT and APX increased under water stress,but increases of superoxide anion content and H₂O₂ content were not related to the levels of stress.(3)The activity of POD rose in Desiree but lowered in Atlantic under drought stress.Compared with Atlantic drought resistant cultivar of Desiree possessed low content of superoxide anion and high activities of POD,CAT and APX under drought stress.Along with the levels of stress 0.01 mmol·L^-1 SNP treatment did not change the tendency of superoxide anion content and H₂O₂ content but changed the tendency of SOD,POD and CAT activities in Atlantic and of APX activity in Desiree.(4) The content of superoxide anion decreased in Desiree under normal water and heavy drought stress and in Atlantic under light drought stress and heavy drought stress by 0.01 mmol·L^-1 SNP.Additionally,SNP increased activities of POD and APX in both Desiree and Atlantic under drought stress.In conclusion,the parameters responsed to drought and drought resistance cultivars in potato were POD,CAT and APX activities.SNP could enhance the drought resistance of potato under drought stress.