Vehicle seat slide device

A vehicle seat slide device includes an elongated lower guide rail adapted to be secured to a floor panel of the vehicle body in its longitudinal direction, and an upper slide rail slidably fitted into the lower guide rail. The lower guide rail has a rail body, side walls, slider rest portions and upper guide walls inwardly extending from upper ends of the side walls to define an elongated guide groove. First hook segments are formed on inner edges of the upper guide walls along the elongated guide groove, and second hook segments are formed on the side walls of the lower guide rail, respectively. The upper slide rail includes a slide body, vertical wall, upper slide walls, and lower side walls. In the upper slide rail, slider rest shoulders, first engaging segments, and second engaging segments are also formed. Either one of the slider rest portions may include a rectilinear portion by which one of the sliders is held in point of contact.