In the framework of cracked plate tbermoelastic problems, the perturbation effects caused by the presence of a crack on thermal stresses, displacements and stress intensity factors in an isotropic linear elastic medium with varying crack surface heat conductivity under uniform heat flow are studied. The disturbance due to the crack results in a non-smooth temperature modihcation of the original field and induces singular character of the thermal stresses near the crack tip. This ~sturbing ante distribution is solved numericafjy by using the distributed dipole me&d, Finite clement solutions under the above temperature distribution are presented. Numerical results of mixed mode stress intensity factors are given for various geometric cases of a plate. It is shown that, for the case of a crack situated in the finite plate center subjected to a uniform heat flow, the geometry does not a&% the mode I thermal stress intensity factor Ki significantly, and Kg is negligible compared with the mode II thermal stress intensity factor Ka. Only the mode II thermal stress intensity factor Ka is significaut and shows a very Iwxdized phenomenon in the nea&eid region of a crack. For all cases studied here, the vaiues of the mode II thermal stress intensity factor in a smaller plate are dependent on the geometric size of the plate. As the geometric size of the plate increases, the value of Kl, is close to the solution of an i&&e plate.