Disclosed is an automotive seat the seat cushion level of which can be adjustable up-and-down, in which the safety is improved when a shock is applied to a vehicle. The automotive seat according to a preferred embodiment of the present invention is equipped with a level adjusting mechanism for adjusting the seat cushion level, and comprises a base frame, a seat cushion, a seat cushion frame, a space from which to the base frame being adjustable, a stopper which supports the sinking seat cushion frame at a rear end collision of an automobile. The stopper moves to narrow the space between the seat cushion frame and the stopper and supports the seat cushion frame.