Abstract: The aggregate used for the Longtan Hydropower Project is crushed from limestone，and the surface of aggregate presents the coated- powder phenomenon easily in the course of transportation. The study content includes the abrasion resistance performances of the aggregate and the characteristics of powder, and the effects of the coarse aggregate coated by powder on the mechanic performance, anti- permeability and frost- resistance capability of concrete by using the blended aggregate of RCC with different powder content. The result shows that the abrasion resistance capability of the aggregate is a little degradation, and that the coarse aggregate coated by powder has a little effects on the mechanic properties of RCC, such as the compressive strength and limiting tensile stress, and on the entrained result of the air- entraining, the anti- permeability and frost- resistance capability of RCC. 