The excess volumes V-E for 1-butanol or 2-butanol or 2-methylpropan-1-ol or 2-methylpropan-2-ol + o-xylene or m-xylene or p-xylene at 308.15 K have been measured over the whole range of composition, The V-E vs composition curves are skewed toward the low concentration of butanol. For systems containing 1-butanol curves are sigmoids and V-E values change sign in the 1-butanol(1) rich region x(1) > 0.8). For butanol + xylene systems V-E values vary in the order 2-methylpropan-2-ol 1 2-butanol > 2-methylpropan-1-ol > 1-butanol.