Abstract: Transfer matrix and transmission coefficients in doping phononic crystal are obtained.Transmission coefficient of elastic waves in doping phononic crystal is calculated.With oblique incidence transversal wave, defect mode of transversal wave decreases with increase of incident angle.Transformation of transversal wave toward longitudinal wave increases with increase of incident angle.With oblique incidence longitudinal wave,defect mode of longitudinal wave decreases with increase of incident angle.Transformation of longitudinal wave toward transversal wave increases with increase of incident angle.

Key words: phononic crystal, elastic wave, transfer matrix, defect mode