An apparatus for controlling the constant current for multi-channel LEDs includes: a plurality of LED channels each comprising an LED array, a transistor, and a variable emitter resistor; a feedback sensing circuit for sensing the collector or drain voltage of a transistor of each of the LED channels; and a controller for increasing the variable emitter resistance of an LED channel in which the collector voltage of the transistor is higher than those of the other LED channels, in response to a feedback sensing result input from the feedback sensing circuit.