A copper-based sliding material including a steel back metal layer and a Cu alloy layer is provided. The Cu alloy layer contains 0.5 to 15 mass % of Sn, 0.2 to 5 mass % of inorganic compound particles and the balance being Cu and unavoidable impurities. The inorganic compound particles are dispersed in a Cu alloy matrix and have an average size of 1 to 10 μm. A ratio of a true density of the Cu alloy matrix in relation to that of the inorganic compound particles is 0.6 to 1.4 and a ratio of a thermal expansion coefficient of the Cu alloy matrix in relation to that of the inorganic compound particles is 1.5 to 3.0. An average distance between the inorganic compound particles dispersed in the Cu alloy matrix is 5 to 50 μm.