Molar excess volumes VE have been measured as a function of mole fraction at 323, 350, and 364 K and at three different pressures around 7.5, 16, and 22 MPa for three binary Liquid systems, 1,4-dioxane + heptane, + tetradecane, and + cyclohexane, by using vibrating-tube densimetry. All excess volumes are positive and show similar temperature and pressure dependence; i.e., V-E increases when temperature increases and decreases when the pressure is increased.