We report the results of the experimental study of the four-wave polar
iton scattering in LiNbO3. Different types of scattering processes and
their mutual influence are considered. Analyzing the angular dependen
ces of the scattering intensity, we show that the cascade coherent typ
e of interaction is predominant in LiNbO3. Perspectives of the measure
ment of refractive indexes and absorption coefficients at polariton fr
equencies are discussed.