The surface exciton-polaritons in ternary mixed crystals are investigated. The numerical calculations for several Ⅲ-Ⅴ and Ⅱ-Ⅵ compound systems are performed and the polariton frequencies as functions of the wave-vector and the compositions for ternary mixed crystals AlxGa1-xAs, CdxZn1-xSe and AlxGa1-xN as examples are given and discussed. The results show that the dependence of the energies of surface polaritons on the composition of ternary mixed crystals are slightly nonlinear different from the bulk modes.