This paper reports experimental values of the interfacial tension between (CO2 + N-2) gas and tetrabutylammonium bromide aqueous solution (TBAB(aq)). The experiments were performed by the pendant drop method in conditions from P = (1.00 to 4.00) MPa, from T = (288.15 to 303.15) K and from w(TBAB) = (0.10 to 0.40), where w(TBAB) denotes the mass fraction of TBAB in the aqueous solution. The interfacial tension decreased with increasing w(TBAB) and pressure. The depletion of the interfacial tension with increasing w(TBAB) in the (CO2 + N-2 + TBAB(aq)) system was consistent with that in (CO2 + TBAB(aq)) system. The depletion ratio of the pressure gradient of the interfacial tension caused by the addition of TBAB in (CO2 + N-2 + water) system was almost the same as that in (CO2 + water) system. There might be little effect on the interfacial tension caused by the interaction between gases and tetrabutylammonium ions. The temperature dependence of gamma was not observed as well as in the (CO2 + TBAB(aq)) system. (C) 2016 Elsevier Ltd. All rights reserved.