A slide rail device for a vehicle seat including a lower rail member fixed on a floor of the vehicle and an upper rail member slidably fitted in the lower rail member. Basically, a stopper and a notch are provided respectively at the forward and rearward ends of the upper rail member, while a striker is provided at the floor of the vehicle, erecting therefrom. When the upper rail member is located at a
home position upon the lower rail member, the stopper is abutted against the forward end of the upper rail member and side of the floor, with the notch being engaged over the striker, whereby the upper rail member is prevented against separation from the lower rail member. Another striker and hook-like lock member may be provided in the case where the vehicle seat is of a jump-seat type having a
seat belt anchor, so that not only the seat is locked to the upper rail member against forward
jumping, but also an upwardly slant pulling force applied through the
seat belt anchor is dispersed and escaped to the floor through the stopper, two strikers, the lock member and the notch. Further, a guide roller arrangement is provided at the upper rail member for supportive sliding in the lower member, which includes a guide piece at one of the guide rollers that will be exposed from the lower rail member when the upper rail member is slid away from the lower rail member, such that the exposed portion of the upper rail member can be withdrawn into the lower rail member, with guiding aid of the guide piece.