In this paper the coupled-wave equations, which involved Hyper-Raman polari-zability of coherent polariton-Raman mixing in polar SHG crystals is presented. The equations have been solved in terme of small signal, phonon and Raman-driven-parametric approximation. The solution shows that coherent polariton-Raman emissions near the double-frequency of pumping lager beam may occur in polar SHG crystals which are driven coherently by the stimulated Raman scattering of theintense pumping beam. The coherent Raman emissions may be directly converted from second harmonic or from fundamental wave beam alone, and also from both waves through different individual processes of coherent Raman mixing. These processes have their own independent phase-mismatohing factors. The latter two processes may ooonr simultaneously in proper case. The conclusion above has been proved true in an experimeni; on crystal LiIO3 in which incident pumping intensity was up to 3.0×109 W/cm2.