PURPOSE: To provide a fluorescent display device to be fitted to a wheel of a bicycle which is capable of recognizing the existence of the bicycle to a third party and luminous even when the bicycle is stopped by providing a notched part on the side of the fluorescent display device, and providing one end of a fitting part.

CONSTITUTION: A body 1 is preferably made of the porous soft plastic material, and the luminous paint is applied to the body. One end 5 of the body is directed toward a wheel rim, one end 3 of a fitting part whose notch is expanded in V-shape is pressed into a spoke shaft of the wheel, and inserted down to the other end 4 of the fitting part into the spoke shaft along a groove in the notched part 2. When the body 1 is fitted to the spoke shaft part of the wheel, the bicycle can be easily recognized by the third party by the luminous display effect not only when the bicycle is traveling but also when it is stopped.