A lighting system for a vehicle is provided. The lighting system includes a sensor module, a control mode, a shutter glass, and a headlamp module. The sensor module senses light entering from outside of the vehicle to generate a sensing signal. The control module generates shutter and lighting operation signals based on the sensing signal. The shutter glass is opened and closed according to the shutter operation signal. The headlamp module has a light source unit that alternately emits a first light having a first luminance and a second light having a second luminance according to the lighting operation signal. The control module controls the shutter and lighting operation signals to enable the light source unit to alternately emit the first and second lights in synchronization with the opening and closing operations of the shutter glass.