Abstract: The temperature field during resistance spot welding with rectangular electrode was simulated using ANSYS.The physical model was properly simplified on the basis of simulation accuracy and technological conditions.One-quarter three-dimensional finite element model during resistance spot welding was built in which the contact resistance was substituted by the electric resistivity.The results show that at the beginning of welding, the edge of electrodes has the highest temperature because of high stress induced by the electrode force.As welding time is longer, the contact resistance decreases and the highest temperature position moves to inside, the nugget appears to be similar with the conventional spot welding.