Abstract: Following an introduction to the structure, working principle and technical features of the teetered-bed separator(TBS), the paper goes to elaborate on the industrial test made at Shenjiazhuang Coal Mine Washery on the effect of upward current on performance of TBS. As evidenced by test result, with the increase of the flow of upward current, the ash of the overflow of TBS is seen to first drop down and then go up, and the presence of high-ash fine coal is a major factor affecting the ash of clean coal product. At the end of the paper, the approaches for optimum selection of upstream and downstream equipment of TBS are proposed.