Abstract: The powders transportation in the plasma arc space during the plasma transferred-are powder surfacing process is theoretical evaluated. The axial accelerating process and radial distribution of axial traveling velocity for various particles along are column section are described. According to the theoretical evaluated results, it is found that the powders axial traveling velocity presents "valley-shape distribution" along plasma are column traverse section when surfacing currents is greater than 150 A. We greater surfacing current is, the deeper and greater,"valley" will be. The theoretical evaluated results also reveal that the particles,accelerating the in the plasma fluid is inversely to its mass density and size. Consequently, for the same powder, the particles with smaller sizes are travelling faster than there with greater sizes. Similar to this, the powders with lee mass density are also transported faster than the powders having a greater mass density.