Abstract: Three kinds of esterification products' mass heat capacities at constant pressure by differential scanning calorimetry were determined, and the expression of mass heat capacities at constant pressure in our needed temperature range was acquired. The constitution of three kinds esterification products were analyzed, the reason why mass heat capacities at constant pressure of the three kinds of esterification products were different was explained by the difference of their constituents. Applying the mass heat capacities at constant pressure to heat balance calculation, the recycle quantity of reaction mixture, an important design parameter of continuous esterification reactor, and the mass of heat medium were acquired. They are very important to the enlargement of esterification reactor.