Abstract:Twodimensional thermoelasticity vibration was analyzed for an orthotropic functionally graded plate with infinite length along ydirection and simple support and constant temperature at two opposite edges in xdirection. According to the basic equations of thermoelasticity, assuming that the material had arbitrary variation property along platethickness direction(zdirection), PeanoBaker series solution was obtained for the thermoelasticity vibration problem of the functionally graded plate with mechanical and thermal loads on upper and lower surfaces by statespace method. The series solution was verified through numerical examples. The influence of forced frequency on structural response of the plate was also investigated with material properties of linear dependence on thicknesscoordinate. The results show that physical quantities of displacements and stresses are increased with the increasing of forced frequency near to the inherent frequency.