The germination and protection enzyme activities of Brassica oleracea L.var.botrytis L.embryo under the different concentration of NaCl and Na₂CO₃ stress were examined in this experiment.The results showed that the germination of broccoli was promoted under the low concentration of NaCl（≤20 mmol/L）.Germination of broccoli was inhibited under the Na₂CO₃ stress when concentration of Na⁺ was the same.SOD and POD activities of embryo under the Na₂CO₃ stress were lower than the NaCl stress,and MDA content was higher than the NaCl stress.Comprehensive analysis showed that the threshold values of broccoli tolerance to NaCl and Na₂CO₃ were 445.5 mmol/L and 64.1 mmol/L.