Abstract: A signal lamp assembly including a casing fixed to the spokes of a bicycle wheel, two tubular, light permeable lampshades connected to two opposite ends of the casing, and a lamp circuit unit installed in the casing and the lampshades and consisting of a battery, a manual switch, a reversing switch, and a series of light emitting diodes disposed in the lampshades and controlled to give light by the manual switch and the reversing switch, wherein the reversing switch is alternatively switched on and off when the bicycle wheel is turned round and round after the manual switch is switched on, causing the light emitting diodes to flash.