The infrared spectra of the benzoyl peroxide symmetrical derivatives (4-R-PhCOO)2 with R: NO2-, CF3-, CF3O-, I-, Br-, Cl-, F-, H-, CH3-, CH3O-were studied by the semiempirical methods. There is a linear relationship between the frequencies of the normal vibrations of the experimental and calculated (PM6, PDDG and AM1) spectra for this series of peroxides. The effect of the DFT level on the normal vibrations frequencies of C = O group of benzoyl peroxide was estimated. The best reproduction of these frequencies is observed in the case of BLYP calculation method with 6-311G (d, p) basis set.