To provide a vehicular seat with lower frames to be deformed upon rear collision but not greatly deformed in the widthwise direction of the vehicular seat upon side collision.

The vehicular seat comprises a pair of lower frames 103, 103' provided on a floor side, on which a seat cushion 111 is arranged, an upper frame 107 rotatably provided on the lower frames 103, 103', on which a seatback is arranged, and reclining mechanisms 109, 109' for locking/unlocking the rotation of the upper frame 107. It has an bent offset portion (a fragile portion) 221 formed on each of lower frames 103, 103' and adapted to be plastically deformed upon rear collision with another vehicle and a rod 131 provided to be bridging between the lower frames 103, 103' with at least one end secured to the lower frame with recess-protrusion fitting.