A backlight module includes a light guide board, at least one light emitting unit, a plurality of first glues, and a first reflection sheet. The light guide board has a light entrance surface, a light exit surface, and at least one reflection surface. The reflection surface is connected to the light entrance surface and the light exit surface respectively. The light emitting unit is disposed at the light entrance surface of the light guide board. The plurality of first glues is alternatively disposed on the reflection surface in a from-sparse-to-dense manner. The first reflection sheet is disposed on the plurality of first glues such that the first reflection sheet can be fixed onto the reflection surface.