A fixing structure and a backlight module using the same are provided. The fixing structure is used for fixing a circuit board. The circuit board with several openings has an upper surface and a lower surface. The fixing structure includes a back plate and several hooks. The back plate has a contact surface. These hooks are disposed on the contact surface. The hooks go through the openings so that the contact surface contacts the lower surface. The hooks move toward the walls of the openings and press against the upper surface so as to fix the circuit board onto the back plate.