Abstract: The three-dimensional state equation was derived for acylindrically orthotropic piezoelectric body with radial polarization.The layerwise method was employed to transform the state equation withvariable coefficients to that with constant coefficients and thestate variable solution was obtained. The free vibration problem of afluid-filled multi-layered piezoelectric cylindrical shell was thenanalyzed. Exact form of frequency equation was presented and numericalresults were obtained.