From spectrograms with dispersion 9-37 A/mm the spectral characteristics of eight eclipsing binary stars have been studied shov/ing the effects of mass exchange. Spectral types of stars have been deterrained as well as temperatures of excitation,
parameters of damping, turbulent velocities, electron number densities, Chemical composition of stellar atmospheres and displacements of lines in radiation and absorption, variations in characteristics of lines, as the function of phase. It is shown that appreciable differences of physical conditions frorn normal ones háae not been observed. Schemes-models of studied stellar systems have been presented and discussed.