Abstract: The physiological and biochemical indexes of Vinca major cv.‘Variegata’grown in pots under salt stress condition were determined and analyzed with the membership function after CaCl₂ treatment, aiming at exploring mitigative effects of CaCl₂ on salt（NaCl）stress. The results showed that soluble sugar content and activities of SOD and POD increased significantly or very significantly when the plants were treated by with CaCl₂ with concentrations of 3 mg/g and 4 mg/g. With the increasing of CaCl₂ concentration root activity and soluble protein content were enhanced under salt concentration of 4 mg/g CaCl₂ treatment could increase net photosynthetic rate significantly under different salt concentrations. Conclusion could be drown from the comprehensive analysis that mitigative effects of CaCl₂ will be enhanced under low or moderate salt stress（3、4 mg/g）and be weakened under the high salt stress（5-7 mg/g）, and that the appropriate CaCl₂ concentration used is from 10 to 20 mmol/L.

Key words: Vinca major cv.‘Variegata’, salt stress, CaCl₂, physiological and biochemical characteristics, membership function