A backlight module (3) includes a light source group (31) and a light guide plate (32). The light source group includes at least a light source, and the light guide plate has a light input surface (321) for receiving light, a light output surface (322) for emitting light, which is adjacent to the light input surface, and a bottom surface opposite to the light output surface and adjacent the light input surface. The light source group faces the light input surface, which is curved such that its curvature matches with the light distribution of the light source group.