Reported salt tolerant-cultivars (Acala 1517-88, Acala 517-SR2) and salt-sensitive cultivars (Deltapine 50, Stoneville 825) were grown for 8 weeks at either 0 or 150 mM NaCl and then analyzed for concentrations of ascorbate (AsA), dehydroascorbate (DAsA), reduced glutathione (GSH), oxidized glutathione (GSSG), and atocopherol. Total ascorbate concentrations did not differ significantly among all the cultivars. AsA concentrations decreased in all cultivars grown at 150 mM NaCl with the two Acala cultivars exhibiting a smaller decrease in AsA than the two salt-sensitive cultivars. Total glutathione and GSSG concentrations were similar in all cultivars at both 0 and 150 mM NaCl. GSH did decrease significantly in the two salt-sensitive cultivars at 150 mM NaCl while the two Acala cultivars showed little change at the high salt level. -Tocopherol concentrations were higher in the Acala cultivars than the salt-sensitive cultivars at both 0 and 150 mM NaCl. When grown at 150 mM NaCl, the two Acala cultivars exhibited a lower DAsA/AsA ratio and a higher GSH/GSSG ratio than the more salt-sensitive cultivars. These data indicate that the salt-tolerant cultivars have a more active ascorbate-glutathione cycle. A more active ascorbate-glutathione cycle and higher constitutive -tocopherol concentrations indicate that the salt-tolerant Acala cultivars have a greater capacity for protection against oxidative damage.