The excess molar enthalpies, H-m(E), are reported for 1-alkanols (2), namely methanol, ethanol, 1-propanol, 1-butanol, and 1-pentanol, in 2-methyl-2-butanol (1) at 298.15 K and at ambient pressure over a range of mole fractions. The H-m(E) data values were negative for all systems over the whole range of composition, and the magnitude of H-m(E) decreases with increasing of chains length. The Redlich-Kister polynomial equation was used to correlate. H-m(E) The excess partial molar enthalpies of 2-methyl-2-butanol, H-m,1(E), and excess partial molar enthalpies of 1-alkanols (C-1-C-5),H-m,2(E) were calculated. The experimental data were used to evaluated the intermolecular interaction functions such as partial derivative H-m,i(E)/partial derivative x(i) and partial derivative H-m,i(E)/partial derivative x(j).