This document summarizes research on the optical properties of polystyrene composites doped with wood buckthorn peel at different concentrations. Samples of pure polystyrene and polystyrene with 2%, 4%, and 6% wood buckthorn peel were created using casting. Absorption coefficient, energy gap, refractive index, and extinction coefficient were determined for the samples using spectroscopy. The results showed the optical constants changed with increased wood buckthorn peel concentration. Absorption decreased with increasing wavelength. Energy gap and optical constants generally depended on crystal structure and atom arrangement. Refractive index increased with photon energy while extinction coefficient varied more at high energies.