In a Pb-free copper-based sintered alloy containing from 1 to 30% of Bi and from 0.1 to 10% of hard matter particles having from 10 to 50 .mu.m of average particle diameter, the Bi phase has a smaller average particle diameter than that of the hard matter particles and is dispersed in the Cu matrix, or the hard matter particles having 50% or less of a contact length ratio with the Bi phase based on the total circumferential length of the hard particle, which are in contact with said Bi phase, are present in a ratio of 70% or more based on the entire number of the hard matter particles.