Modal analysis is employed to analyze the vibration of temperature-dependent of Functionally Graded Plates (FGP) under a thermal environment in order to determine the natural frequencies and mode shapes. Theoretical formulation of various materials’ properties is done using the rule of mixtures. The natural frequencies and mode shapes of simply supported and clamped square plates are investigated as a function of crack, cutout, crack and cutout and temperature dependent properties. The Ansys program is employed for the purpose of analyzing the natural frequency and mode shape of a plate. Non-dimensional results are compared for temperature-dependent and temperature-independent FGP and subsequently validated according to known results obtained from the literature. Numerical results indicate the effect of crack, cutout, gradient index and temperature fields on the vibration characteristics and mode shapes. This study proves that natural frequency decreases with increasing gradient index ( ) increasing the temperature and simultaneous presence of crack-cutout. In addition, clamped plates have a higher frequency than simply supported plates in all cases. Increasing temperatures lead to a maximum decrease in frequency at clamped FGP.