We demonstrated a characterization method of entropy‐change measurement for the study of the electrocaloric effect (ECE). After the specific heat capacity was measured under different applied fields using a differential scanning calorimeter (DSC) accompanied with DC power supply, the electrocaloric ΔS was calculated from the temperature integral of specific heat capacities based on the basic definition of entropy. The ΔS–T curve of BaTiO3 single crystal showed a sharp peak around Tc, which increased gradually and shifted to higher temperature with the rise of applied field. A high ECE with ΔS = 1.9 J/kg K and ΔT = 1.6 K is achieved under a quite low field of 10 kV/cm. The results agreed with the thermodynamic calculation. It provides a direct, precise, and time‐efficient method for the electrocaloric studies.