A light emitting device and a driving method thereof, and a method for reducing motion blur and flicker phenomena of a display is provided. A light emitting device for providing light to a display that displays images is provided. The device includes: a display unit that includes scan lines, column lines, and light emission pixels, the scan lines respectively applied with first scan signals and second scan signals during one frame period; a local brightness controller that generates a dimming signal having brightness information of the light emission pixels, generates motion flag signals having motion information corresponding to the light emission pixels, and generates ratio control signals having division information of the dimming signal according to the motion flag signals; and a controller that divides the dimming signal into first divided dimming data and second divided dimming data according to the ratio control signals.