Reinforcement structure for seat belt attachment part of vehicle

The purpose of the invention is to ensure sufficient strength with respect to the load from a seat belt 2803, and strive to keep the vehicle body light in weight. A rear pillar inner panel 12, along with a corresponding portion of an outer panel 10, constitutes a rear pillar 22. A seat belt anchor 28 for supporting the seat belt 2803, which is used in the rear seat of the vehicle, is attached to the rear pillar inner panel 12. A quarter inner panel 14 is disposed between a rear door opening part 18 and the rear pillar inner panel 12, and the rear part of the quarter inner panel 14 is integrally joined to the rear pillar inner panel 12, with the remaining sites of the quarter inner panel 14 being joined to the outer panel 10. An irregularly shaped bead part 30 extending along the direction in which load is applied from the seat belt 2803 to the seat belt anchor 28 is provided to a lower lateral part 14D of the quarter inner panel 14. 目的在于对来自安全带(2803)的负荷确保充分的强度并实现车身的轻量化。后柱内板(12)与外板(10)的对应的部分起构成后柱(22)。在后柱内板(12)上