A vehicle seat with a seat cushion and a seat back, the vehicle seat comprising: right and left side frames constituting right and left frames of the seat back; a pressure-receiving member disposed between the right and left side frames and configured to receive a load from an occupant; and a driving mechanism disposed at each of right and left sides of the pressure-receiving member and configured to cause a right end portion or a left end portion of the pressure-receiving member to move from an initial position to an advanced position that is located frontward of the initial position or to move from the advanced position to the initial position, wherein the driving mechanism comprises a linkage configured to be connected to the pressure-receiving member and a driving source configured to actuate the linkage, wherein the linkage includes a link member configured to be rotatable frontward and rearward relative to the side frame and connected to the pressure-receiving member, and is configured to operate when a load equal to or greater than a predetermined amount is input from the occupant to the pressure-receiving member to cause the pressure-receiving member to move to a backward position that is located rearward of the initial position, characterized in that the vehicle seat comprises a rotation resistive member configured to restrict a rearward rotation of the link member (100, 200) when a load smaller than the predetermined amount is input from the occupant to the pressure-receiving member and to deform when a load equal to or greater than the predetermined amount is input from the occupant to the pressure-receiving member so as to allow a rearward rotation of the link member. right and left side frames constituting right and left frames of the seat back; a pressure-receiving member disposed between the right and left side frames and configured to receive a load from an occupant; and a driving mechanism disposed at each of right and left sides of the pressure-receiving member and configured to cause a right end portion or a left end portion of the pressure-receiving member to move from an initial position to an advanced position that is located frontward of the initial position or to move from the advanced position to the initial position, wherein the driving mechanism comprises a linkage configured to be connected to the pressure-receiving member and a driving source configured to actuate the linkage, wherein the linkage includes a link member configured to be rotatable frontward and rearward relative to the side frame and connected to the pressure-receiving member, and is configured to operate when a load equal to or greater than a predetermined amount is input from the occupant to the pressure-receiving member to cause the pressure-receiving member to move to a backward position that is located rearward of the initial position, characterized in that the vehicle seat comprises a rotation resistive member configured to restrict a rearward rotation of the link member (100, 200) when a load smaller than the predetermined amount is input from the occupant to the pressure-receiving member and to deform when a load equal to or greater than the predetermined amount is input from the occupant to the pressure-receiving member so as to allow a rearward rotation of the link member.