A half bearing constituting a cylindrical plain bearing for supporting a shaft for rotation when two of the half bearings are combined together. The half bearing has two circumferential ends each of which has a plurality of circumferential grooves without formation of any crush relief surface. The grooves extend substantially over an overall circumferential dimension of the half bearing and include portions located at both circumferential ends of the half bearing respectively. Each portion has a larger axially sectional area than the grooves formed in a portion of the half bearing mainly subjected to load during rotation of the shaft.