A light emitting device with a dimming visible light communication function and an interaction device applying for visible light are provided. The light emitting device with the dimming visible light communication function comprises a luminance adjusting unit, a control circuit and a light emitting device. The luminance adjusting unit outputs a luminance adjusting signal according to luminance adjusted by a user. The control circuit coupled to the luminance adjusting unit outputs a pulse width modulation (PWM) signal according to the luminance adjusting signal. The light emitting device outputs visible light, receives the PWM signal, and is turned on or off according to states of a logic high voltage and a logic low voltage of the PWM signal. In an idle mode, the PWM signal operates at a first frequency. In a light communication mode, an operating frequency of the PWM signal is changed according to transmitted data.