A valve seat of an iron-based sintered alloy having high wear resistance in a wide temperature range, which can be used in direct injection engines with improved fuel efficiency, low emission and high power, is obtained by limiting the amount of a solid lubricant dispersed in the matrix of the valve seat of an iron-based sintered alloy, and dispersing at least two types of hard particles having different hardnesses in the matrix, thereby providing high strength and self-lubrication, as well as improved wear resistance under no lubrication in a wide temperature range.