A centrifugally cast, hot-rolling composite roll comprising an outer layer formed by a centrifugal casting method, and an inner layer made of ductile cast iron and integrally fused to the outer layer; the outer layer having a chemical composition comprising by mass 1.6-3% of C, 0.3-2.5% of Si, 0.3-2.5% of Mn, 0.1-5% of Ni, 2.8-7% of Cr, 1.8-6% of Mo, 3.3-6.5% of V, and 0.02-0.12% of B (or 0.01-0.12% of B, and 0.05-02% of S), the balance being Fe and inevitable impurities, and meeting the relation expressed by Cr/(Mo+0.5W)≧−2/3[C−0.2(V+1.19Nb)]+11/6, wherein W=0, and Nb=0, when W and Nb are not contained, and containing by area 1-15% of MC carbide, 0.5-20% of carboboride, and 1-25% of Cr-based carbide.