Abstract: The factors affecting tangential resistance between coal and working parts,such as water content of coal and normal pressure,are analyzed.Results show that there is obvious interaction between water content of coal and normal pressure when there is affecting tangential resistance.For lower normal pressure,tangential resistance increases with the water content.For higher normal pressure,the relationship between tangential resistance and water content is consistent with quadratic parabola.Surface electroosmosis method can reduce coal tangential resistance,but the pole distribution affects the result of reducing resistance.When the area rate between positive plate and negative pate is 1:3,the maximum of reduction for tangential force is 8.8%.

Key words: coal, adhesion, electroosmosis, tangential resistance