Samples of 2,4,6-trinitrotoluene (TNT) exposed to heat or to shock and residues after their detonation have been analyzed chromatographically (LC-UV and LC/MS). It was found that the main identified decomposition intermediates are identical in all the three cases. 4,6-Dinitro-2,1-benzoisoxazole and 2,4,6-trinitrobenzaldehyde are the most reactive from them. It has been stated that the chemical micro-mechanism of the primary fragmentations of shock-exposed TNT molecules and/or its detonation transformation should be the same as in the case of its low-temperature thermal decomposition.