The present invention discloses a backlight module and a liquid crystal display (LCD) thereof. The backlight module comprises a backplane and a heatsink plate attached to the backplane, and the backlight module of the LCD also comprises at least one press plate, wherein the press plate is attached to the heatsink plate to tightly press the heatsink plate against the backplane. Because a press plate is added in the present invention to tightly press the heatsink plate, the press plate reduces the gaps formed between the places away from the attaching points because of small pressure. Therefore, thermal contact resistance is reduced, the heat in the cavity of the backlight is conducted to the metal backplane in time, and the temperature of the backlight module is reduced.