An organic light emitting display device capable of driving transistor threshold voltage compensation, including: pixels positioned in the intersections of scan lines and data lines, wherein each pixel comprises: a first transistor and a fourth transistor, connected at a common node, disposed between an anode of an OLED and a first power supply; a cathode of the OLED connected to a second power supply; a second transistor connected between a gate of the first transistor and a data line, and turned on when a scan signal is supplied to a scan line; a third transistor connected between the common node and the data line, and turned on when a scan signal is supplied to the scan line; a first capacitor connected between the gate of the first transistor and the anode of the OLED; and a second capacitor connected between the anode of the OLED and a predetermined voltage source.