The Baeyer-Villiger (B-V) reactions of 3,4-dimethoxy acetophenone (DMOAP), 4-methyl acetophenone (MAP), and acetophenone (AP) with performic acid (PFA) in formic acid (FA) solvent have been studied by density functional theory (DFT) method. The noncatalyzed and the formic acid-catalyzed reaction paths have been calculated at the MPWB1K/6-311++G(d,p)-1EF-PGM// MPWB1K/6-311G(d,p) level of theory. On the basis of the calculations, the attack of peracid to the carbonyl carbon is rate-determining in both the noncatalyzed and acid-catalyzed paths. The selective oxidation of 3,4-dimethoxy acetophenone and 4-methyl acetophenone by performic acid into aromatic esters have been experimentally investigated. The kinetic rate constants were obtained in the temperature range of 303 to 323 K. The selectivity of product was also explained by the NBO electric charge analysis. The calculated activation energy barriers of the B-V reaction of DMOAP and MAP were in good agreement with those of experiment.