A bearing apparatus for a crankshaft of an internal combustion engine having a main bearing and a connecting rod bearing is provided. The main bearing comprises a pair of semi-cylindrical bearings, only one of which has an oil groove extending in a circumferential direction on an inner circumferential surface thereof. The oil groove is separated from an axial groove formed at a joint portion of the semi-cylindrical bearings by a separation inner circumferential surface of which a length L1 in the circumferential direction is smaller than a length L2 of an inlet opening of a journal portion in the circumferential direction. The connecting rod bearing also comprises a pair of semi-cylindrical bearings, and has axial grooves and crush reliefs with appropriate dimensions at joint portions thereof.