On　the　basis　of　the　Von　Karman　theory　and　piezoelectric　theory,　and　considering　the　linearly　thickness　variation　in　one　direction,　the　dimensionless　nonlinear　differential　equations　of　motion　for　the　symmetric　angle-ply　laminated　piezoelectric　rectangular　plates　with　linearly　varying　thickness　are　established.　The　Galerkin　procedure　furnishes　an　infinite　system　of　equations　for　time　functions　which　are　solved　by　the　method　of　harmonic　balance.　The　problem　for　nonlinear　vibration　of　symmetric　angle-ply　laminated　piezoelectric　rectangular　plates　with　linearly　varying　thickness　is　investigated.　In　the　numerical　results,　the　influences　of　different　taper　constant,　aspect　ratio　and　various　ply　angles　on　the　nonlinear　vibrating　frequency　response　curves　of　the　simply　supported　symmetric　angle-ply　laminated　piezoelectric　rectangular　plates　are　discussed.