Abstract: Based on the classical plate theory, the equilibrium and stability equations of a rectangular plate made of functionally graded material subjected to thermal loading condition are derived. The material properties are assumed to vary as a power form of thickness coordinate variable. Closed form solutions for a simply supported rectangular plate made of functionally graded material under uniform heat change are presented. The influences of the plate aspect ratio, relative thickness of plate functionally gradient index, and displacements of neural plate plane on the buckling temperature difference are discussed.