A vehicle seat frame which is lightweight and strong includes a seat cushion frame supporting a seat cushion, a seat back frame supporting a seat back, a recliner rotatably connecting the seat back relative to the seat cushion and adjusting the rotation angle thereof and a shoulder belt anchor provided on the seat back frame for supporting one end of a shoulder belt. The back center frame of the seat back frame includes a hollow quadrangular shape outer peripheral portion and a reinforcement plate provided in the outer peripheral portion and placed in parallel with a direction of load to be applied on the shoulder belt anchor from the shoulder belt.