Abstract：The seed vigor，antioxidant enzyme activities and photosynthetic pigment of cauliflower （Brassica oleracea L．var．botrytis L.）‘Yinnong 70 tian’were studied under NaCl stresses with concentration as 0，34，68，102，136，170，204 mmol?L-1．It was found that the seed germination percentage，germination energy，germination index，Chla/Chlb and Car/Chl ratio were reduced linearly under NaCl stresses，while malondialdehyde（MDA）content was just the opposite with NaCl stress．The parabola curves in superoxide dismutase（SOD）activity，seedling fresh and dry weight，Chla，Chlb，Chl and Car contents were observed with increasing NaCl stresses and the highest values were obtained under 68-136 mmol?L-1 NaCl stresses|while pattern of the relative ratio of salt disease was the opposite and the lowest value was obtained under 34 mmol?L-1 NaCl stress．The patterns of the peroxidase（POD）and catalase（CAT）activities were displayed different response to salt stresses．Specially，the activities of POD and CAT increased under moderate salty stress，while decreased under severe stress（204 mmol?L-1）．It was suggested that the relative ratio of salt stress（136 mmol?L-1），SOD，POD，CAT activities and Chla，Chlb，Chl and Car contents were sensitive indicators that could effectively reflect the response pattern of the physiological and biochemical activities of cauliflower seeds under NaCl stress，but the germination percentage，germination energy，germination index，Chla/Chlb and Car/Chl ratios could not．For cauliflower seeds，the 102-136 mmol?L-1 NaCl was the threshold at which the negative effect of salt stress on seed vigor and some physiological and biochemical characteristics．
