Abstract: Taking into account the effect of temperature dependency of material properties, the transient thermal stresses in functionally gradient material (ZrO₂ and Ti-6Al-4V)(FGM) plate under convective heat transfer boundary are analyzed by the nonlinear finite element method. The accuracy of this method is examined by comparison with previous references. The stress distributions under the different states of deformation are obtained and compared with the results of constant material properties. The numerical results show that the stresses in the infinitely long traction-free plate of FGMs are the smallest. When the bending of a plate is only limited, the tensile stresses in the plate are maximum. It is also found that the compressive stresses are maximum when the elongation and the bending of a plate are limited. When the temperature dependency of the material properties is considered, the maximum compressive and tensile stresses are 39.6% and 48.9% less than those of the FGMs with constant material properties, respectively. In addition, the stress distributions are influenced substantially by convective heat transfer coefficients. The results of this paper provide the foundations of theoryand computation for the design and application of the FGMs.