To provide a vehicular seat slide gear that is less in the number of part items, capable of lightening its own weight as specified and also able to reduce the cost of production, as making smooth operations performable, besides preventing any offensive sound from occurring.

A vehicular seat slide gear is equipped with a grooved metal rail 1 to be set up in a car body, a slider 3 being installed in a seat and free of movement in the longitudinal direction, and a bearing 5 supported by this slider 3. In this constitution, a contact surface member 12 is attached tight to an outer ring 7 so as to make this contact surface member 12, consisting of resin or rubber, interpose between this outer ring 7 of the bearing 5 and the rail 1.