The salt-tolerant mechanism of Sedum aizoon seedling under different concentrations of NaCl solution(50,100,200,400 mmol/L)was studied by measuring the fresh weight,SOD,POD,CAT,MDA,Pro,soluble sugar after treating for 0,3,7,15 and 30 days.The average daily growth amount of fresh weight was increased 4.8% under 50 mmol/L,and no significant change was found under 100 mmol/L,it was decreased 9.2% under 200 mmol/L and died under 400 mmol/L.The contents of MDA,SOD,POD,CAT,Pro and soluble sugar were increased alo...