The vacuole ion accumulation is of crucial importance for adaptation of plants to salt stress. The Na⁺ transport from the cytoplasm into the vacuole via the tonoplast Na⁺/H⁺ antiport is V-ATPase and V-PPase activities dependent. The establishment of an electrochemical H⁺-gradient across the tonoplast supplies energy for Na⁺ transport against a gradient concentration. The aim of this study was to analyze salt-induced changes in the expression of the vacuolar H⁺-ATPase subunit A (V-ATPase). Vigna unguiculata (L.)Walp cv. Vita 3 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). Assays were performed using 1, 3, and 14 days transferred plants leaves.The protein level of V-ATPase subunit A in plant treated for 14 days was evaluated by Western blotting using antibodies against Mesembriathenum crystallinum V-ATPase subunit A and the transcript level in all conditions was evaluated by RT-PCR using specific primers for V. unguiculata. The RT-PCR analysis showed that transcrip levels in plants under 100 mM NaCl increased in all days tested revealing the greatest value for 14 days with concomitant increase of the protein level for V-ATPase subunit A. The results suggest that an up-regulation of V-ATPase subunit A seems to be a strategy of Vigna unguiculata plants to self-defense against to salt stress.