To offer a bearing device for a vehicle wherein fretting abrasion can be inhibited and prevented by reducing a relative hardness difference between connection faces of a turnable ring and a connection member small and rasing the wear resistance between the contact faces.

The bearing device for a vehicle comprises a rolling bearing A pivoting an axle S of various vehicles turnably, a stationary ring 4 and turnable rings 2a and 2b oppositely arranged relatively turnably through two or more rolling bodies 6a and 6b and annular positioning members F, P for positioning the turnable ring in the axial direction. The positioning member and the turnable rings have their end surfaces opposite to each other in the axial direction arranged in contact with each other, and can be turned together with the axle. The difference in hardness between the end surfaces F1, P1 of the positioning member and the end surfaces 2e, 2f of the turnable rings in contact with the end surfaces is 20 or less in the Rockwell hardness C scale.