The present invention discloses a backlight control circuit capable of distinguishing an under current condition, comprising: at least one light emission device path having a voltage node; at least one current source for controlling the current amount on the light emission device path; and at least one under current detection circuit for generating a first control signal according to the voltage at the voltage node, wherein when the first control signal changes its state, the under current detection circuit generates a second control signal to change the voltage on the voltage node if the light emission device path is normally connected.