Provided is a sliding member for a journal bearing. The sliding member includes a back-metal layer and a sliding layer, and has a partially cylindrical shape. The sliding layer includes a synthetic resin and has a sliding surface. 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 center axis 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 (1) and (2): Relation (1): 1.1≤KS/KJ≤2; and Relation (2): 1.3≤KT/{(KS+KJ)/2}≤2.5.