A composite roll for rolling comprising an outer layer and an inner layer integrally fused to each other; the outer layer being made of an Fe-based alloy comprising by mass 1-3% of C, 0.3-3% of Si, 0.1-3% of Mn, 0.1-5% of Ni, 1-7% of Cr, 1-8% of Mo, 4-7% of V, 0.005-0.15% of N, and 0.05-0.2% of B; the inner layer being made of graphite cast iron comprising by mass 2.4-3.6% of C, 1.5-3.5% of Si, 0.1-2% of Mn, 0.1-2% of Ni, less than 0.7% of Cr, less than 0.7% of Mo, 0.05-1% of V, and 0.01-0.1% of Mg; the inner layer comprising a core portion fused to the outer layer, and shaft portions integrally extending from both ends of the core portion; at least one of the shaft portions containing 200/cm2 or more of hard MC carbides having circle-equivalent diameters of 5 μm or more.