Theoretical calculations have been performed to predict the antioxidant property of phenolic compounds extracted from Artocarpus altilis. The OH bond dissociation enthalpy (BDE), ionization energy (IE), and proton dissociation enthalpy (PDE) of the phenolic compounds have been computed. The ONIOM(ROB3LYP/6-311++G(2df,2p):PM6) method is able to provide reliable evaluation for the BDE(OH) in phenolic compounds. An important property of antioxidants is determined via the BDE(OH) of those compounds extracted from A. altilis. Based on the BDE(OH), compound 12 is considered as a potential antioxidant with the estimated BDE value of 77.3kcal/mol in the gas phase.