A sliding member for a thrust bearing, the sliding member comprising: a back-metal layer ; and a sliding layer on the back-metal layer , wherein the sliding member has a partially annular shape, wherein the sliding layer has a sliding surface , and comprises: a synthetic resin ; optionally 1 to 20 volume % of one or more solid lubricants selected from graphite, molybdenum disulfide, tungsten disulfide, boron nitride, and polytetrafluoroethylene; optionally 1 to 10 volume % of one or more fillers selected from CaF 2 , CaCO 3 , talc, mica, mullite, iron oxide, calcium phosphate, potassium titanate, and Mo 2 C; and optionally 1 to 35 volume % of one or more types of fibrous particles selected from glass fiber particles, ceramic fiber particles, carbon fiber particles, aramid fiber particles, acrylic fiber particles, and polyvinyl alcohol fiber particles, and characterized in that, in a center line region of the sliding layer, the sliding layer has a linear expansion coefficient KS in a direction parallel to a circumferential direction of the sliding member, a linear expansion coefficient KJ in a direction parallel to a radial direction of the sliding member, and a linear expansion coefficient KT in a direction perpendicular to the sliding surface , and the linear expansion coefficients KS, KJ and KT satisfy the following relations and : 1.1 ≤ KS/KJ ≤ 2; and 1.3 ≤ KT/ KS + KJ / 2 ≤ 2.5 . a back-metal layer ; and a sliding layer on the back-metal layer , wherein the sliding member has a partially annular shape, wherein the sliding layer has a sliding surface , and comprises: a synthetic resin ; optionally 1 to 20 volume % of one or more solid lubricants selected from graphite, molybdenum disulfide, tungsten disulfide, boron nitride, and polytetrafluoroethylene; optionally 1 to 10 volume % of one or more fillers selected from CaF 2 , CaCO 3 , talc, mica, mullite, iron oxide, calcium phosphate, potassium titanate, and Mo 2 C; and optionally 1 to 35 volume % of one or more types of fibrous particles selected from glass fiber particles, ceramic fiber particles, carbon fiber particles, aramid fiber particles, acrylic fiber particles, and polyvinyl alcohol fiber particles, and characterized in that, in a center line region of the sliding layer, the sliding layer has a linear expansion coefficient KS in a direction parallel to a circumferential direction of the sliding member, a linear expansion coefficient KJ in a direction parallel to a radial direction of the sliding member, and a linear expansion coefficient KT in a direction perpendicular to the sliding surface , and the linear expansion coefficients KS, KJ and KT satisfy the following relations and : 1.1 ≤ KS/KJ ≤ 2; and 1.3 ≤ KT/ KS + KJ / 2 ≤ 2.5 . a synthetic resin ; optionally 1 to 20 volume % of one or more solid lubricants selected from graphite, molybdenum disulfide, tungsten disulfide, boron nitride, and polytetrafluoroethylene; optionally 1 to 10 volume % of one or more fillers selected from CaF 2 , CaCO 3 , talc, mica, mullite, iron oxide, calcium phosphate, potassium titanate, and Mo 2 C; and optionally 1 to 35 volume % of one or more types of fibrous particles selected from glass fiber particles, ceramic fiber particles, carbon fiber particles, aramid fiber particles, acrylic fiber particles, and polyvinyl alcohol fiber particles, and characterized in that, in a center line region of the sliding layer, the sliding layer has a linear expansion coefficient KS in a direction parallel to a circumferential direction of the sliding member, a linear expansion coefficient KJ in a direction parallel to a radial direction of the sliding member, and a linear expansion coefficient KT in a direction perpendicular to the sliding surface , and the linear expansion coefficients KS, KJ and KT satisfy the following relations and : 1.1 ≤ KS/KJ ≤ 2; and 1.3 ≤ KT/ KS + KJ / 2 ≤ 2.5 . <EOS>