The invention relates to a power supply for a liquid crystal display using a light emitting diode for a backlight unit, and more particularly, to a power supply combining a DC power supply outside the liquid crystal display with a driving power supply inside the liquid crystal display into a single power supply. The power supply for a liquid crystal display according to an aspect of the invention may include: a power conversion section converting commercial AC power into at least one operating power having a predetermined voltage level through a switching operation; a backlight driving section switching the operating power from the power conversion section into backlight driving power; and a power switching control section controlling the switching operation of the power conversion section on the basis of a first feedback signal having a voltage level of the operating power from the power conversion section and a second feedback signal having a voltage level of the backlight driving power from the backlight driving section, wherein the power conversion section, the backlight driving section and the power switching control section are mounted on a single printed circuit board.