In recent years,the properties of the surface polaron in polar crystals in a magnetic field have been of considerable interest.Larsen proposed a fourth order perturbation method to calculate the ground state energy of two dimensional polaron in a magnetic field.Wei et al. studied the cyclotron resonance mass and resonance frequency of the interface magnetopolaron using the Green’s function method.The properties of surface polaron in a magnetic field have been discussed by linear combination operator method by the present authors and co workers. In fact,so far research on the surface magnetopolaron was restricted to the approximation and calculation where the interaction of the surface electron with LO and SO phonons is considered,whereas the interaction of the surface electron with SA phonon is neglected.So far,the research on the quasi particle,the acoustic deformation potential (ADP) polaron,formed by the interaction of electrons with acoustic lattice vibration is very scarce. In this paper,the properties of the surface magnetopolaron interacting with the deformation potential in polar crystals,which has a weak coupling with surface optical phonon and surface acoustic phonon,are studied .The effective mass of the surface magnetopolaron interacting with the deformation potential in polar crystals is derived by using linear combination operator method.