Abstarct: Existence of cracks in the structure, causes structural failure at loads less than the expected ones. So investigating the behaviour of crack in orthotropic materials, is essential. On the other hand, many of the structures and machinery are exposed the temperature gradient or high temperature. According to the research, the thermal failure is one of the conventional failure mode of structures. In this thesis, the Extended finite element method is implemented to compute the dynamic fracture parameters (stress intensity factors and T stress) in 2D orthotropic media under thermal loading. a single laxyer orthotropic rectangular plane is considered. this plane is exposed to cooling thermal shock at the cracked side, other sides are assumed insulated. In this thesis, The uncoupled thermoelasticity equations are considered. Isoparametric four-node and eight-node rectangular elements are used to discrete governing equations. The dynamical stress intensity factors and Tstress are computed by the interaction integral method. The Newmark method is used for the time integration of the equilibrium equations and the Crank–Nicolson scheme is applied to solve the classical heat conduction equations. In this thesis, a MATLAB code is developed to carry out all stages of the calculations from mesh generation to post-processing. In several numerical examples, dynamic stress intensity factors (SIFs) and T stress are compared to the analytical and numerical reports. is drawn an analogy between obtained results and other numerical or analytical method. proposed results and the reported results are in good agreement.