This invention is intended to provide an improved structure of wheel rim frame of bicycle, wherein a stripe sticker printed with fluorescent patterns is attached onto a bottom portion of the wheel rim frame, and a protective membrane is further attached onto the sticker, so that, by favor of the printed patterns and the protective membrane, a diversified wonderful feeling is offered by the wheel rim frame to meanwhile remind people of being alert and to protect the improved structure from being scraped to prolong usable life; and besides, this invention can be employed to cooperate with wheel rim frame of various shapes or efficacies, and owing to simplified process, a lower manufacturing cost is achievable.