Abstract: The mass spectrometric kinetic method based on the competitive dissociations of mass-selected cluster ions has been increasingly applied to thermochemical determination mainly due to its simplicity, speediness and sensitivity. Because the kinetic method employs tandem mass spectrometry, the compounds of interest need not be available in pure form. The kinetic method has been used to estimate gas-phase acidity and basicity and proton affinity, electron affinity, ionization energy, gas-phase basicities of multiply-charged biomolecules, metal ion affinities, heterolytic bond dissociation energies, chiral recognition and quantification. In this paper the theory of kinetic method is introduced in detail and its applications are enumerated.