To lighten a car body and reduce cost by simplifying the mounting part structure of a rear grab rail on seat rails without provision of a cross- member to couple together the tails of the seat rails.

A motorcycle is configured so that a left and a right seat rail 45 are stretched backward from the rear of the body frame, a seat is attached onto these seat rails, and a rear grab rail 60 is installed behind the seat and in the rear of the two seat rails. The rear grab rail consists of a member having a square shape on the plan composed of a cross-member 61 to work also a cross-member for the seat rails and a grip bar 62 in approx. U-form extended from the left and right ends of the cross-member.