An ambient light system applied in a TV including a display panel, a loudspeaker and a plurality of ambient light sources includes an audio level detector, a pattern generator, and an ambient light controller. The audio level detector detects the level of an input audio signal to obtain a detected level. The pattern generator generates an ambient light pattern based on the detected level by reference to a selected operation mode. The ambient light controller controls the intensity of one or more ambient light sources based on the ambient light pattern.