Abstarct: Abstract: In this research, circular cracks located at the interface of two homogeneous and different isotropic solid materials subjected to thermal loading are investigated and analyzed. During the construction of the thermal barrier coating, it is inevitable to create pores and cracks between the laxyers. Also, low thermal expansion coefficient may cause cracks. These defects reduce the bond strength of the interface and lead to the creation and propagation of interfacial cracks. Surface crack propagation depends on crack stress intensity coefficients, so it is necessary to investigate the effect of structural parameters on interface crack stress intensity coefficients. Thermal stresses are one of the main causes of interfacial failure between dissimilar materials, which result from differences in thermal expansion coefficients. To solve the problem in this thesis, the coupled classical thermoelasticity equations are used. These equations will be discretized using the developed finite element method in space and solved in time using the Newmark method. The method of solving the coupled classical thermoelasticity equations is explained with the help of the developed finite element method. In this research, to determine the stress intensity coefficients, the interaction integral parameter, which is one of the important parameters in crack evaluation, is calculated. By calculating the interaction integral, the stress intensity coefficients of mode I and mode II can be calculated separately. In this research, how to implement this method in MATLAB and determine the starting angle of crack growth is investigated. Solving the relevant equations and extracting the results has been done in the MATLAB programming environment. The results of this research provided a better and more accurate understanding of the behavior of circular cracks and more effective design of structures and materials to resist thermal loads.