The motion of grinding media was visualized on three types of blade (normal disk type, hole disk type and cross type) for a horizontal type sand mill of which internal blade and external cylinder rotate inversely and independently. As a result, the effect of blade geometry on velocity distribution, the intensity of velocity fluctuations and appearance frequency of grinding media was made clear. The relationship between these flow characteristics and grinding rate was discussed by carrying out grinding tests of calcium carbonate. As a result, it is found that the grinding characteristics obtained for each blade in both rotation methods can be well correlated with the intensity of velocity fluctuations weighted by appearance frequency. A new type of blade (cross turbine type) was produced based on the above information, and its grinding rate was investigated in connection with the motion of the grinding media. The results showed that it has a higher rate of grinding than the three types of blades previously used.