A backlight module including a back board, a reflector, at least one light source, at least one lens unit, and a light leakage feature is disclosed. The reflector includes a base and at least one side wall connected to the base and is disposed on the back board. The light source is disposed on the board and emits light. The lens unit is disposed on the light source and configured to diffuse the light emitted from the light source for generating light rays impinging on the side wall. The light-leakage feature is disposed at the side wall and configured to allow some of the light rays to pass through the side wall.