The surface optical phonon effects on the low lying energy states of the surface impurities in isotropic semiconductors are studied by a variational perturbative approach proposed recently. The ground state and the first excited state energies of the surface polaron are calculated. Numerical results for III-V compounds InP, InAs and InSb are obtained. It is found that the surface phonon effects on the energy levels of the surface impurity atom in these semiconductors are small. To make an explicit comparison we also apply our approach to calculate the ground polaron state energy of GaAs. The result shown in the contribution of the electron-SO phonon interaction is not so large as obtained in the previous conventional variational method.