Antioxidant defense system provides protection against oxidative damage caused by abiotic stresses including salinity. Ameliorative effects of l-proline, l-glutamine, glycine betaine (GB) on growth, proline accumulation and antioxidant enzyme activities were studied using cultured cells of sugarcane against salt (NaCl) stress. NaCl stress reduced growth rate significantly over the control however, proline or glutamine supplementation resulted in growth revival. Proline supplementation to media with or without salt increased accumulation of free proline significantly than the controls and other (proline, GB and glutamine) treatments. Salt stress led to increase in superoxide dismutase (SOD) and glutathione reductase activity whereas guaiacol peroxidase (GPX), catalase and ascorbate peroxidase activities were significantly suppressed. Proline supplementation to the salt medium improved the GPX activity over the salt media supplemented with glutamine or glycine betaine. The activity ratio between SOD and H2O2 scavenging enzyme activities, which is considered as a working hypothesis for biochemical marker for salt tolerance, was lower in salt medium supplemented with proline. Thus, the higher growth rate and the lower activity ratio suggest maximum salt stress ameliorative potential of proline in sugarcane cultured cells.