The present invention relates a display device and a method for driving the same which can improve a picture quality. The display device can include a histogram generation/analysis unit for analyzing image data, generating a histogram of the image data to each of the frames, and analyzing the histograms, a gamma reference voltage generating unit for generating gamma reference voltages and adjusting magnitude of the gamma reference voltages according to a result of analysis and forwarding the gamma reference voltages adjusted, a timing controller for re-arranging the image data, controlling output timings of the image data re-arranged and forwarding the image data re-arranged, and a data driver for generating gamma gradient voltages by using the gamma reference voltages, converting the image data into analog image signals by using the gamma gradient voltages and supplying the analog image signals to a display panel.