Studies were carried out to determine the activity of complexes of the essential amino acids DL-Lysine and L-Methionine with heavy metals in the oxidation of cyclohexene with tert-butylhydroperoxide in toluene at 80°C. All complexes were prepared through interaction of metal ions and DL-Lysine and L-Methionine at room temperature in aqueous solutions. Only the complexes of Mo and W were obtained from acidic aqueous solution. These complexes were characterized by FT-IR, Moessbauer spectroscopy and EPR analysis. The products of the oxidation reactions were identified by GC/MS analysis. The complexes of Mo and V showed the best activity in the epoxidation reaction of cyclohexene in comparison with other complexes, such as Ni, Mn, Zn, Co, Cu, Cr, Fe and W. Using semi-empirical quantum-chemistry methods, the full energy of the Mo complexes was calculated and their probable structure is presented.