The enthalpies of solution and the thermodynamics of styphnic acid 2,4,6-trinitroresorcinol (TNR) the solution solved in DMF were studied. The enthalpies of TNR solution with different concentrations were measured by a SETARAM C80Ⅱcalorimeter at 298.15 K and the empirical formula for enthalpies of TNR solution is calculated by polynomial simulation on the computer. The results show that the formula is Δ_solH=-14.392-988.6b+34.992b^1/2. The standard molar enthalpy of solution is determined to be Δ_solH^θ_m=-14.392 kJ·mol^-1. The relative apparent molar enthalpies of solution (ΦL_i), the relative partial molar enthalpies(L_i), enthalpies of dilution (Δ_dilH_1,2) are also stretched respectively. The thermodynamics of TNR solution was studied by analyzing heat-flux to time curves, the rate constant of reaction and the reaction order were determined to be 1.632×10^-3 s^-1 and 0.6158, respectively.