Recently, the fabrication of the extra-coarse-grained WC-Co cemented carbide has aroused wide interests for useful applications as mining bits or shield cutting tools. In this study, extra-coarse-grained WC-10Co cemented carbides were sintered using ball-milling-mixed composite powders, and the inner relationship of mechanical properties with microstructural evolution was investigated systematically. The average particle size of mixed WC-10Co powders decreased rapidly from about 20 μm to 2 μm by extending milling time from 3 h to 12 h, and then kept stable at about 1 μm with increasing ball milling time further. (nhnhanh)