The cucumber(Cucumis sativus L.)variety‘Xintaimici’was hydroponically cultured to study the effects of different exogenous concentration Ca(NO₃)₂ on growth of cucumber seedlings and membrane lipid peroxidation under salt stress(NaCl 65 mmol·L^-1).The results showed that exogenousCa(NO₃)₂ of different concentration could alleviate the growth inhibition,reduce the increasing range of MDA and electrolyte leakage rate caused by salt stress.2.0 mmol·L^-1 Ca(NO₃)₂ is the best treatment.The above soil fresh quality of cucumber seedling,its dry quality,plant height,stem thickness,leaf areas,under ground fresh weight,dry weight,total root length,total root areas,total root size,number of root tips,etc-other growth index were significantly higher than those under single salt stress treatment.At the same time,the MDA content and the increasing electrolyte leakage rate under salt stress were also decreased.