A display device and a driving circuit thereof are disclosed. In one aspect, the display device includes a display panel, a gamma reference voltage generator, a data driver and a driving controller. The display panel includes a plurality of pixels, each pixel including first and second sub-pixels. The gamma reference voltage generator generates one or more first gamma reference voltages each having a high gamma value greater than a reference gamma value, and one or more second gamma reference voltages each having a low gamma value less than the reference gamma value. The data driver generates a data voltage based at least in part on one or more of the first and second gamma reference voltages, and provides the data voltage to the first and second sub-pixels. The driving controller determines a gamma value and a data voltage output pattern according to a driving method of the display panel.