A backlight module includes first and second light emitting layers. The first light emitting layer is disposed above the second light emitting layer and each includes at least one light guide plate and light source disposed next to the respective light guide plate. Each light guide plate has at least one light transmissive region and light exit region. Each light transmissive region of the first light emitting layer corresponds to each light exit region of the second light emitting layer. Each light exit region of the first light emitting layer corresponds to each light transmissive region of the second light emitting layer. Each light source is next to each light transmissive region. Each light transmissive region is between each light source and light exit region. Each light exit region of the first light emitting layer corresponds to each light transmissive region and light source of the second light emitting layer.