Abstarct: In this thesis, stress intensity factors and T stress for an insulating crack in a thermoelectric environment under thermal shock have been calculated using the eXtended Finite Element Method. Thermoelectric properties of the plate are temperature dependent. The nonlinear governing equations are firstly discreted in the domain of space by the eXtended Finite Element Method and then solved by Newmark's integration method in the realm of time. In some numerical examples, the effect of thermal shock on the stress intensity factor and T stress is investigated. The stress intensity factors in the thermal-electric loading are increased with the arrival of the stress wave to the thermal crack tip. According to the results of this research, T stress has a significant effect on the starting angle of the crack. T stress initially increased at constant zero in the time zero, and then, with the maximum value at constant time and proportional to the displacement, the trend was reduced, and then the T stress was stable. Parameter B initially increases at the time of zero to a maximum value, and then decreases, and then it becomes constant in proportion to the time and radius of the tip of the crack.