To provide an installing structure for ornamental members of a vehicle, free from defective fixation due to displacement during installation, capable of coping with structural problems in a wheel arch or with aging changes, and allowing the installing work to be carried out quickly, surely, and easily.

In an installing structure for a wheel arch molding 4, or an ornamental member of a vehicle, which is attached along a wheel arch part of a side body, an engaging claw 7 and a guiding boss 8 are projected/disposed from/on the installing surface side of the arch molding 4, while a bracket 9 is installed in the wheel arch part of the side body. In the bracket 9, a locking part 10 for locking an engaging claw 7 is disposed, while a boss hole 11 for insertion of a guiding boss 8 is made.