For investigating the physico-chemical properties of thorium and its compounds, differential scanning calorimetry (DSC) has been employed for measuring the molar heat capacity (C-p) of ThO2 in the temperature range 373-773. Even though C-p values of thoria are available in the literature, DSC has been used for the first time in the present work as it is sensitive, fast, simple and requires small sample size. The DSC curve obtained was desmeared to obtain the true heat flow rate, which was, then used to compute the C-p values. A number of sample-dependent and the operator-dependent parameters were optimized, to obtain the results within the best possible precision and accuracy. With proper control of different influencing parameters it was possible to obtain the results within an accuracy and precision of 10%.