Abstract: During seed germination，seven different concentrations of NaCl solution（0. 5，1. 0，2. 0，3. 0，5. 0，7. 0，9. 0 g/L）were used to study the response of three different varieties of kidney beans under NaCl stress. All the three varieties of kidney beans showed the trend that high concentrations of NaCl solution decreased seed germination rate，germination potential，germination index，vigor index，root length，bud length，lateral root number，fresh weight，SOD activity while increased the MDA content of seedlings. However，the effects of low concentrations on seed germination index， seedling growth index and physiological index were related to the concentration of NaCl and the variety of kidney bean. The results of comprehensive evaluation of membership function showed that the salt tolerance of the three varieties was in the order: safflower white kidney bean > Xiza 2 (wide) kidney bean > Xiza 2 kidney bean.

Key words: kidney bean, seed germination, seedling growth, membership function, salt tolerance