This chemical reactivity theory study was conducted on ten (10) molecules of a series of dihydrothiophenone (DH) substituted by the quantum chemical method using density functional theory, at the B3LYP/6-31G (d, p) level. A set of global and local descriptors were used to assess the reactivity of the molecular systems. In addition, the most relevant quantum chemical descriptors for the action of the molecule as an inhibitor, such as the highest occupied molecular energy (E<SUB>HOMO</SUB>), the lowest vacant molecular orbital energy (E<SUB>LUMO</SUB>), the energy gap (ΔE), the dipole moment (μ), electronegativity (χ), overall hardness (η) and overall softness (Ѕ) on the heteroatoms were calculated. The analysis of the thermodynamic formation quantities confirmed the formation and existence of the studied series of molecules. The study of the boundary molecular orbitals provided a better overview of the molecular activities. The analysis of the global descriptors revealed that the DH1 molecule has the lowest value of energy gap. This lower gap allows it to be the most reactive (soft) and the least stable molecule. Also we note that it has the lowest hardness, but the highest softness. This indicates that it is the most electrophilic of all the compounds.