In this paper we present the Raman scattering measurements of the ZnSe epilayers grown on (001) GaAs substrate by molecular beam epitaxy method. We have studied dependence of the frequency shift of LO(ZnSe) mode in the Raman spectra vs. thickness of the ZnSe layer. The intensity of LO(ZnSe)/LO(GaAs) ratio vs. orientation angle α of the E vector of the exciting light on the ZnSe/GaAs interface relatively to the sample orientation is presented too.