A copper base alloy exhibits improved wear resistance particularly at elevated temperatures, which consists essentially of, in percent by weight, 10-40% of Ni, 1-7% of Si, 0.5-5% of B, 1-20% of Cr, and the balance of Cu, wherein particles of at least one of chromium boride and chromium silicide having a size of about 0.1 to about 50 .mu.m are evenly dispersed in a copper-nickel base matrix. The alloy may further contain W, Mo or Fe and/or a high-melting carbide such as WC and TaC.