In　this　paper,　the　nonlinear　dynamics　of　a　simply　supported　functionally　graded　materials　(FGM)　conical　panel　with　different　forms　of　initial　imperfections　is　investigated.　The　conical　panel　is　subjected　to　the　simple　harmonic　excitation　along　the　radial　direction　and　the　parametric　excitation　in　the　meridian　direction.　The　small　initial　geometric　imperfection　of　the　conical　panel　is　expressed　by　the　form　of　the　Cosine　functions.　According　to　a　power-law　distribution,　the　effective　material　properties　are　assumed　to　be　graded　along　the　thickness　direction.　Based　on　the　first-order　shear　deformation　theory　and　von　Karman　type　nonlinear　geometric　relationship,　the　nonlinear　equations　of　motion　are　established　by　using　the　Hamilton　principle.　The　nonlinear　partial　differential　governing　equations　are　truncated　by　Galerkin＇s　method　to　obtain　the　ordinary　differential　equations　along　the　radial　displacement.　The　effects　of　imperfection　types,　half-wave　numbers　and　amplitudes　on　the　dynamic　behaviors　are　studied　by　numerical　simulation.　Maximum　Lyapunov　exponents,　bifurcation　diagrams,　time　histories　and　phase　portraits　are　obtained　to　show　the　dynamic　response.　©　Copyright　2017　ASME.