Two calorimetric methods: solution and direct reaction method were used for determination of the formation enthalpy of titanium aluminides – candidates for high-temperature application. The special construction of solution calorimeter enables to determine enthalpy of formation at various temperatures what was realized for Al3Ti compound. The differences between results obtained by solution method and direct reaction technique grows with the decrease of aluminium content in the phases – this tendency was explained by mechanism of formation of phases from powders – in particular by the sequence of phases formation. Comparison with results of Calphad estimation of formation enthalpy and of theoretical ab initio calculation is also included.