Abiotic stresses as salt stress are known to act as a catalyst in producing free radical reactions resulting in oxidative stress in various plants where reactive oxygen species (ROS) such as superoxide radical (O₂ -), hydroxyl radical (.OH), hydrogen peroxide (H₂O₂) and alkoxyl radical (RO.) are generated. Whitin a cell, the superoxide dismutases (SODs) constitute the first line of defense against ROS and increased SOD activity is known to confer oxidative stress tolerance. SODs are classified into three groups: iron SOD (Fe SOD), manganese SOD (MnSOD) and copper-zinc SOD (Cu-Zn SOD). The Fe SOD activity was considered as H₂O₂ sensitive, the CuZn as KCN and H₂O₂ sensitive and Mn SOD as the insensitive activity for KCN and H₂O₂. The aim of this report is to understand the effect of salt stress on growth in the whole plant and on SOD activity from Vigna unguiculata (L.) Walp  roots and leaves. V. unguiculata seeds were dark germinated, at 28°C, during 3 days and than transferred to a growth chamber with a photoperiodism of 12 hours in Hoagland’s medium and grown in the absence (control) or presence of NaCl (100 mM) for two weeks. The plant growth was inhibited by 100mM NaCl revealing a reduction of 52 %, 31 % and 51% in roots, shoots and leaves respectivily. The total SOD activity was 70 % increased in roots and 65 % decreased in leaves from plants under salt stress compared to control condition. In leaves, the Fe-SOD activity was detected only in control condtion, the CuZn activity was 47 % decreased while Mn SOD activity was 17 % increased in response to salt stress. The results showed that SOD enzymes appear to protect only V. unguiculata roots against oxidative stress suggesting a differential regulation in different plant tissues.