The total vapor pressure of liquid mixtures of (xenon + n-butane) has been measured at 182.34 and 195.49 K, and of (xenon + isobutane) at 195.49 K. The liquid: molar volumes have also been measured at 182.34 K for both systems. The mixtures follow the behavior already found for other (xenon + alkane) mixtures, i.e., negative deviations from Raoult＇s law, negative excess molar Gibbs energies (G(m)(E)) and negative excess molar volumes (V-m(E)). The excess molar enthalpy (H-m(E)) is approximately zero in the case of (xenon + n-butane). The results were interpreted using the statistical association fluid theory for potentials of variable attractive range (SAFT-VR). This study provides further evidence that the (xenon + n-alkane) mixtures can be thought of as a particular case of mixtures of n-alkanes.