A slide structure of a vehicle seat which positions a seat cushion in a longitudinal direction of a vehicle comprises a stationary outer rail which extends in the longitudinal direction of the vehicle and is fixed on a vehicle floor and includes a substantially C-shaped cross section an opening portion of which is oriented inwardly in the widthwise direction of the vehicle and is disposed to exhibit an elongated cross section in the vertical direction of the vehicle, and a movable inner rail which extends in the longitudinal direction of the vehicle and fits over said stationary outer rail so as to be slidable in the longitudinal direction of the vehicle relative to said stationary outer rail and is fixed on the seat cushion and includes a substantially C-shaped cross section an opening portion of which is oriented outwardly in the widthwise direction of the vehicle and is disposed to exhibit an elongated cross section in the vertical direction of the vehicle, said movable inner rail fits with said stationary outer rail with the opening portions formed by the respective substantially C-shaped cross sections facing each other in such a way that, in a case where said seat cushion is positioned to be in the most front position, a front end of said movable inner rail protrudes forwardly from a front end of said stationary outer rail, while, in a case where said seat cushion is positioned to be in the most rear position, a rear end of said movable inner rail protrudes rearwardly from a rear end of said stationary outer rail, characterized in that said slide structure further comprises a slide cover (500A, 500B) which is provided on an end portion of the stationary outer rail and includes a substantially C-shaped cross section, said slide cover (500A, 500B) fits over said movable inner rail in the longitudinal direction with its opening portion formed by the substantially C-shaped cross section being oriented outwardly in the widthwise direction and includes an end face (504A, 504B) whose inner surface contacts an end of said stationary outer rail, the longitudinal length of said slide cover (500A, 500B) is set to be longer than a distance from said end of said stationary outer rail on which said slide cover (500A, 500B) is provided to an end of said movable inner rail when said movable inner rail reaches a position where said end of said movable inner rail at the side of said end of said stationary outer rail is situated to be the farthest from said end of said stationary outer rail, said slide structure further comprises a means for biasing said slide cover (500A, 500B) toward said stationary outer rail one end of which is fixed on said slide cover (500A, 500B), and wherein in case where the slide cover (500A, 500B) is provided on the front end portion of the stationary outer rail and the seat cushion is positioned to be the most front position, when the movable inner rail is moved forwardly relative to the stationary outer rail, the front end of the movable inner rail contacts the inner surface of the end face (504A, 504B) of the slide cover (500A, 500B), the slide cover (500A, 500B) is moved forwardly along with the movable inner rail being guided along the movable inner rail. a stationary outer rail which extends in the longitudinal direction of the vehicle and is fixed on a vehicle floor and includes a substantially C-shaped cross section an opening portion of which is oriented inwardly in the widthwise direction of the vehicle and is disposed to exhibit an elongated cross section in the vertical direction of the vehicle, and a movable inner rail which extends in the longitudinal direction of the vehicle and fits over said stationary outer rail so as to be slidable in the longitudinal direction of the vehicle relative to said stationary outer rail and is fixed on the seat cushion and includes a substantially C-shaped cross section an opening portion of which is oriented outwardly in the widthwise direction of the vehicle and is disposed to exhibit an elongated cross section in the vertical direction of the vehicle, said movable inner rail fits with said stationary outer rail with the opening portions formed by the respective substantially C-shaped cross sections facing each other in such a way that, in a case where said seat cushion is positioned to be in the most front position, a front end of said movable inner rail protrudes forwardly from a front end of said stationary outer rail, while, in a case where said seat cushion is positioned to be in the most rear position, a rear end of said movable inner rail protrudes rearwardly from a rear end of said stationary outer rail, characterized in that said slide structure further comprises a slide cover (500A, 500B) which is provided on an end portion of the stationary outer rail and includes a substantially C-shaped cross section, said slide cover (500A, 500B) fits over said movable inner rail in the longitudinal direction with its opening portion formed by the substantially C-shaped cross section being oriented outwardly in the widthwise direction and includes an end face (504A, 504B) whose inner surface contacts an end of said stationary outer rail, the longitudinal length of said slide cover (500A, 500B) is set to be longer than a distance from said end of said stationary outer rail on which said slide cover (500A, 500B) is provided to an end of said movable inner rail when said movable inner rail reaches a position where said end of said movable inner rail at the side of said end of said stationary outer rail is situated to be the farthest from said end of said stationary outer rail,