A backlight module includes a circuit board, a plurality of light emitting units, a support frame, a reflector, and a diffusion plate. The light emitting units are disposed on the circuit board. The support frame includes a plurality of first support members, wherein the first support members are disposed on the circuit board in parallel. The reflector is disposed on the support frame. The reflector includes a plurality of reflecting grids, wherein the reflecting grids are accommodated between the first support members and the light emitting units are located in the reflecting grids. The diffusion plate is disposed above the reflector.