Abstract: A striker further excellent in durability is provided. A striker for a vehicular opening/closing member of the invention includes a base plate made of a steel penetrated with a post hole, and a post projected from the base plate by being caulked in a state of inserting an end portion of a rod member made of steel to the post hole. An inner face of the post hole is formed with at least one groove recessed in an outer direction of a diameter relative to an axis center of the post hole. The end portion clamps a surface side edge and a back face side edge of the post hole and is made to plastically flow at inside of the groove.