A backlight driving circuit is disclosed. The backlight driving circuit includes a steady voltage circuit, a boost converter, a current setting circuit, and a control circuit. The steady voltage circuit receives an input voltage, filters the input voltage and outputs a steady DC voltage. The boost converter connects to the steady voltage circuit to receive the steady DC voltage. The control circuit provides a first PWM square wave such that the boost converter may supply power to the LED light bar. Wherein the boost converter includes a first MOSFET or a triode. At least three parallel connected resistors are arranged between a source of the first MOSFET or a collector of the triode and the ground, and the three resistors have the same or similar resistance. In addition, a liquid crystal display includes the backlight driving circuit is also disclosed.