In this work, the refractive indices (nD) of binary mixture of diisopropylamine (DIPA) and tributylamine (TBA) (as sec- and tert-amines) with alkanol (methanol, ethanol, 1-propanol, 2-propanol) were measured from 298.15 K to 318.15 K. The sec- and tert-amines were selected to study the effect of branching at N-atom of amine on intermolecular interactions with alkanols having different chain length. It was found that the TBA interacts strongly with alkanol in comparison to DIPA due to steric hindrance offered by isopropyl group at N-atom. Various mixing rules were applied to evaluate the refractive index compared well with the experimental refractive indices data for the present binary mixtures. The experimental refractive indices was also fitted to Redlich-Kister polynomial.