A method for sensing degradation of an organic light emitting display includes an initialization step for applying a sensing data voltage to a gate node of a driving TFT and applying an initialization voltage to a source node of the driving TFT, a boosting step for floating the gate node and the source node of the driving TFT and applying a drain-to-source current of the driving TFT to an organic element, a sensing step for again applying the initialization voltage to the source node of the driving TFT, setting a gate-to-source voltage of the driving TFT depending on a degradation degree of the organic element, and storing the drain-to-source current of the driving TFT determined by the set gate-to-source voltage in a line capacitor, and a sampling step for outputting a voltage stored in the line capacitor as a sensing voltage.