The electronic structures study have been used in the classification of tocopherol-rings regiosiomers as antioxidants by quantum chemistry calculations using DFT methods at the B3LYP/6-31G * level of theory. The HOMO, ionization potential, stabilization energies, and spin density distribution calculations were performed for radical formed by electron or hydrogen abstraction from the phenolic hydroxyl groups at the para-, meta-or ortho-positions. These values are related with HOMO and MEPs for antioxidant regioisomers classification. Our results shown that para-regioisomer is more nucleophilic compounds by electron transfer and more reactive molecule by hydrogen donating, followed by ortho-, and meta-regioisomers.