An illuminating flexible flat cable includes a plurality of first cables, a plurality of light sources and a first controller. Each of the first cable includes an electric conductive member and a light guiding member and the electric conductive member is coated and covered by the light guiding member. One of the first cables is a power first cable, and the electric conductive member of the power first cable is adapted for being electrically connected with a first power source, while the light sources are arranged corresponding to the first cables. The light emitted by each of the light sources is guided into the cables and transmitted in the light guiding members. However, at least a portion of the light can penetrate the light guiding members. The first controller is electrically connected with the light sources to control the light sources to emit the light. The first controller is also electrically connected with the electric conductive members of the power first cables so that the electric conductive members enable the first power source to provide electrical power for the first controller and the light sources.