The present invention provides a circuit for controlling a color sequential liquid crystal display (LCD) and a method for controlling the same. The control circuit comprises a light-source driving circuit, a data driving circuit, and a scan driving circuit. The light-source driving circuit produces a driving signal for controlling the color sequential LCD to produce backlight with different colors. The data driving circuit produces a data signal and includes a plurality of data pulses. The scan driving signal produces a scan signal and includes a plurality of scan pulses corresponding to the plurality of data pulses, respectively. By controlling the pluralities of data pulses and scan pulses and the backlight, the color sequential LCD will display an image. The voltage levels of the pluralities of data pulses and scan pulses change according to different images. Thereby, power consumed by the control circuit can be reduced. In addition, color-mixing problems will be reduced according to the present invention.