The present invention discloses a liquid crystal display (LCD) and a backplane of a back light module thereof. The LCD comprises a back cover, one or more circuit boards and a backplane of a back light module. One or more circuit board attaching devices for attaching the circuit boards are arranged on the interior sidewall of the back cover and void spaces for avoiding the circuit boards are arranged at the corresponding position of the backplane. As the circuit boards installed prior to this invention on the backplane is now installed on the back cover instead, the backplane of the back light module of the LCD is not provided with the bumps for attaching the circuit boards any more; the structure of the backplane and the manufacturing process of the backplane are simpler. Furthermore, as the back cover is insulated, the bumps are not arranged, and the circuit boards can be attached by simple circuit board attaching devices, significantly simplifying the process.