A bearing device for a crankshaft of an internal combustion engine, comprising: a crankshaft having a plurality of journal portions (61, 62) and a plurality of crank pin portions; main bearings (41, 42) for supporting the crankshaft; and a bearing housing for holding the main bearing (41, 42), wherein the plurality of journal portions includes a first journal portion with a lubricating oil passage for feeding oil to the crank pin portions of the crankshaft, and a second journal portion without the lubricating oil passage, the first journal portion is supported by a first main bearing, and the first main bearing includes a pair of an upper-side halved bearing and a lower-side halved bearing each having a half-cylindrical shape, the second journal portion is supported by a second main bearing, and the second main bearing includes a pair of an upper-side halved bearing and a lower-side halved bearing each having a half-cylindrical shape, the bearing housing includes an upper-side housing and a lower-side housing, the upper-side housing has a half-cylindrical surface aligned with an outer circumferential surface of the upper-side halved bearing, the lower-side housing has a half-cylindrical surface aligned with an outer circumferential surface of the lower-side halved bearing, the upper-side halved bearing (41U, 42U) is held on the half-cylindrical surface of the upper-side housing, and the lower-side halved bearing (41L, 42L) is held on the half-cylindrical surface of the lower-side housing, an inner oil passage for supplying oil to the first and second main bearings is formed inside the upper-side housing, and an opening (G2c) of the inner oil passage is formed on the half-cylindrical surface of the upper-side housing, the upper-side halved bearings (41U, 42U) out of the pair of halved bearings have at least one oil hole, the upper-side halved bearing of the first main bearing has an oil groove, the oil hole penetrates a bearing wall thickness of the upper-side halved bearings (41U, 42U), and is open on an outer circumferential surface, the opening (G2c) of the inner oil passage of the upper-side housing and the oil groove of the upper-side halved bearing of the first main bearing communicate with each other through the oil hole, the opening (G2c) of the inner oil passage of the upper-side housing and an inner circumferential surface of the upper-side halved bearing of the second main bearing communicate with each other through the oil hole, each of the upper-side and lower-side halved bearings (41U, 41L, 42U, 42L) has crush reliefs formed at both circumferential end portions of an inner circumferential surface thereof, characterized in that lengths of the crush reliefs of the upper-side and lower-side halved bearings (41U, 41L) of the first main bearing are the same as each other, and a length of the crush relief of at least the upper-side halved bearing of the second main bearing or a length of the crush relief of each of the upper-side and lower-side halved bearings (42U, 42L) of the second main bearing is larger than the length of the crush relief of each of the upper-side and lower-side halved bearings (41U, 41L) of the first main bearing.