Abstract: The oxidation of Zr-2 alloy weldment during the condenser discharge resistance seam welding has been studied.A 0.5Be-2.5Co-Cu alloy is selected as the electrode material,which has high resoftening temperature and high resistance to the deformation of the electrode during welding.The Zr-2 alloy was welded in air with instantaneous super-high heating rate.In the case of keeping condenser discharging time constant,the thickness of oxidation layer on the workpiece increased with the increase of the energy stored in the condensers.The thickness of oxidation layar decreased with the decrease of condenser discharging time when the energy stored in condenser remained constant.