There are provided a plain bearing which is excellent in oil retaining property and wear-resistant property. The plain bearing has a number of fine grooves which are formed in the circumferential direction on each of the inner surfaces of semi-cylindrical bearing metals. Lands are defined as portions of the plain bearing which are left between the fine grooves. The lands comprise higher projecting lands and lower projecting lands. With this arrangement, a rotating shaft is supported by the higher projecting lands and a large amount of lubricating oil can be retained between the higher projecting land and the next higher projecting land thereto. Consequently, the bearing and its associated rotating parts can be prevented from the possible seizure in the running-in period at the early stage when using the bearing, which is liable to cause the seizure in particular. Even when frictional wear of the higher projecting lands is in progress, because of a large amount of lubricating oil retained in the fine grooves between the adjacent lower projecting lands, the plain bearing is excellent in anti-seizure property and wear-resistant property.