SEAT SLIDE DEVICE FOR VEHICLE

A plurality of rolling members, which are retained by retainers between sidewall-portion inside operating surfaces formed on inside surfaces of sidewall portions of a lower rail and sidewall-portion outside operating surfaces formed on outside surfaces of sidewall portions of a first upper rail, roll in contact on the sidewall-portion inside operating surfaces and the sidewall-portion outside operating surfaces; sidewall portions of a second upper rail are cut and raised at parts of only a predetermined length in a vehicle front-rear direction to be formed as rolling-element rolling portions having sidewall-portion outside operating surfaces; and rolling element circulation units each incorporating a plurality of rolling elements are fitted on the rolling-element rolling portions, so that the plurality of rolling elements roll and circulate in contact with the sidewall-portion inside operating surfaces and the sidewall-portion outside operating surfaces.