Provided is an organic light emitting diode (OLED) display device including a plurality of pixels to display images, each of the pixels including an OLED, a driving transistor connected to the OLED, and a switching transistor configured to supply data signals to the OLED, the device including: a sensor configured to sense a change amount of a mobility of the driving transistor; a compensation value calculator configured to obtain a change amount of a threshold voltage of the driving transistor based on the sensed change amount of the mobility; and a data compensator configured to adjust the data signals based on the sensed change amount of mobility and the obtained change amount of the threshold voltage.