The　nonlinear　free　vibration　for　viscoelastic　cross-ply　moderately　thick　laminated　composite　plates　under　considering　transverse　shear　deformation　and　damage　effect　is　investigated.　Based　on　the　Timoshenko-Mindlin　theory,　strain-equivalence　hypothesis,　and　Boltzmann　superposition　principle,　the　nonlinear　free　vibration　governing　equations　for　viscoelastic　moderately　thick　laminated　plates　with　damage　are　established　and　solved　by　the　Galerkin　method,　Simpson　integration,　Newton-Cotes,　Newmark,　and　iterative　methods.　In　the　numerical　results,　the　effects　of　transverse　shear,　material　viscoelasticity,　span-thickness　ratio,　aspect　ratio,　and　damage　effect　on　the　nonlinear　free　vibrating　frequency　of　the　viscoelastic　cross-ply　moderately　thick　laminated　plates　are　discussed.　Copyright　©　2010　Y.　F.　Zheng　and　L.　Q.　Deng.