The present invention an organic light emitting diode display device includes a display panel having a plurality of pixel regions, a gate driving unit for driving gate lines and light emitting control lines of the display panel, a data driving unit for driving data lines of the display panel, a power supply unit for supplying first and second power signals to power lines of the display panel as well as a compensating voltage to a compensating power line, and a timing controller for controlling the gate and data driving units for displaying an image with a data voltage compensated with the compensating voltage and controlling the power supply unit to supply the compensating voltage after converting a level of the compensating voltage just before display of a first image on the display panel at an initial driving.