Abstract It has been shown that tumor cells are resistant to radiation and that increasing tumor oxygen levels via laser-mediated hyperthermia treatment increases tumor cell radio sensitivity. Hence, studies of the effects of laser irradiation on tumor oxygen levels are of great interest, as they allow for the optimization of hyperthermia treatment. Accordingly, in this study is to develop a finite element model to simulate the heat transfer due to laser irradiation of tumor tissue, the blood flow through a tumor capillary, and the effect of changing temperature on blood flow rates and oxygen delivery to tumor tissue and. This can be achieved by using finite element models using COMSOL Multiphysics software (FEM lab).