When a Cu—Sn—Bi had—particle based sliding material is used for sliding, Cu of Cu matrix flows and covers up Bi phase. Seizure resistance lowers as time passes. A Pb-free sliding material preventing the reduction of seizure resistance is provided. (1) Composition: from 1 to 15% of Sn, from 1 to 15% of Bi, from 0.02 to 0.2% of P, and from 1 to 10% of hard particles having an average diameter of from 50 to 70 μm, with the balance being Cu and unavoidable impurities. (2) Structure: Bi phase and the hard particles are dispersed in the copper matrix, and all of said hard particles are bonded to the copper matrix.