In this test,under low,moderate and high gradients of saline alkali,we studied the response of physiological and biochemical indexes of six hybrid hazelnuts (Corylus heterophylla Fisch.×C.avellana L.) in the sapling stage to saline alkali stress soil in Xinjiang,and made comprehensive appraisal by using the method of principal component analysis and membership function.The results showed that:(1)With the increase of the soil salinity gradient,the cell electrolyte leakage rate and the accumulation of malondialdehyde quantity of six hybrid hazelnuts all increased.Among them,the increase ranges of electrolyte leakage rate for XZ1 and XZ3 were the highest (HD minus LD＞100%) while the increase range of LZ8 was the lowest (HD minus LD only about 4%);The increase range of the accumulation of malondialdehyde quantity for XZ4 was the highest (HD minus LD is 23.94%),while XZ2 was the lowest (HD minus LD is 7.06%).(2)Chlorophyll content showed a decrease trend with the increase of the soil salinity radient.Among them,the decline range of XZ3 was the highest (LD minus HD is 32.55%).Osmotic regulation substances,such as proline content were rising first and then reducing.The variation laws of soluble protein,soluble sugar contents and the activity of the SOD and POD among six cultivars were different.(3)Having stronger ability of osmotic adjustment and the activity of protective enzymes,LZ3 and XZ1 showed stronger adaptability to saline soil saline alkali soil.A comprehensive analysis showed the adaptation of LZ3,XZ1,LZ8,XZ4,XZ3 and XZ2 to the saline alkali soil orderly declined.