Abstract: A simplified model on the anode sheath region was introduced which was based on the magneto-hydrodynamic model, and the fluid flow and heat transfer in a DC plasma arc was simulated. To study the influence of anode sheath region on the DC arc, statistical analysis was carried out on the simulation results calculated at four different conditions. The anode sheath region had a strong effect on the anode heat flux and shear stress, but less significant effect on the maximum temperature of the arc and its temperature contours. Therefore, the anode sheath of the arc not only reduced the heat transfer efficiency, but also enhanced the instability of the anode bath interface.