The continuous specific heat capacities at constant pressure (C_p) of 2,4,6-trinitro-1,3,5-trihydroxybenzene(TNPG), mono-substituted sodium (Na₁TNPG), di-substituted (N_a2TNPG) and tri-substituted (Na₃TNPG) trinitrophloroglucinate were measured by differential scanning calorimeter (DSC) method. The change of enthalpy and entropy were calculated at an interval of 5 ℃ in the range from 50 ℃ to 100 ℃. The temperature dependence of C_p were determined from the experimental values as C_p(J·g^-1·℃^-1)=a+bT+cT²+dT³ with the exception d=0 for the substituted sodium salts of TNPG. The deviation analysis indicates that DSC method is effective and can be used to measure the specific heat capacity of other energetic materials. The correlation coefficients that are close to 1 show that the C_p values of these compounds are well-regulated.