The present invention provides a valve seat having a suitable degree of wear resistance, which can be produced without recourse to expensive elements represented by cobalt and at a cost lower than ever before. This valve seat is formed of a wear-resistant sintered alloy having a general composition consisting essentially of, in weight ratio, 0.736 to 5.79% of nickel, 0.12 to 6.25% of chromium, 0.294 to 0.965% of molybdenum, and 0.508 to 2.0% of carbon with the balance being iron, and inevitable impurities, and having a micro structure wherein a bainite matrix structure or a mixed bainite and sorbite matrix structure includes a nucleus having a hard phase composed mainly of chromium carbide, and a ferrite surrounding said nucleus and having a high chromium concentration and a martensite surrounding said ferrite are dispersed.