An organic light emitting display device includes pixels positioned at crossing regions between data lines and scan lines, each of the pixels including an organic light emitting diode, a scan driver configured to supply a scan signal to scan lines, a data driver configured to drive the data lines, wherein the data driver includes, in each channel, a supply part comprising a digital-to-analog converter configured to generate data signals using second data supplied from outside in a driving period, and a deterioration part configured to measure deterioration information of the organic light emitting diode using the digital-to-analog converter in a sensing period.