Sound speeds (u) were measured and excess isentropic compressibilities (KSE) were computed from the measured sound speed (u) and density (ρ) data for the binary liquid mixtures of m-xylene with o- and m- nitrotoluenes at T= (298.15 K, 303.15 K, 308.15 K and 313.15 K). These values are negative for the studied binary liquid mixtures. The excess isentropic compressibilitiy (KSE) values are analysed on the basis of molecular interactions between unlike non-electrolyte molecules.