By using of the magnetohydrodynamic effect of electrical current, a new aspect of CO 2 laser beam welding of aluminum with an electrical current technique was reported. A DC power source was used to supply current to the weld pool. One pole of the source was connected with a tungsten electrode which was set in front of the weld pool and the other with the work piece in the rear of the weld pool. In so doing a closed electrical circuit was built. When the electrical current flows in the weld pool, a magnetic field is induced and electromagnetic forces are generated in it, which change the fluid flow and the heat exchange condition of the weld pool. So far the experimental results have shown that the weld depth and area increase and the weld seam becomes more slender when the current is up to a certain value, e.g. 200 A. In the experimental conditions, the weld depth increases maximum nearly by 32% and the weld area nearly by 20%, but the weld width decrease maximum nearly by 28%.