Provided is an organic light emitting display device, which comprises: a display panel containing a plurality of pixels; a control unit for outputting an image signal received from the outside by correcting in accordance with an amount of a voltage drop generated; a data driver for supplying a data signal corresponding to the image signal; a scan driver for supplying a scan signal to a scan line; a load factor calculation unit for deducing a load factor of a panel; a horizontal block load factor calculation unit for deducing a load factor of a horizontal block and a driving current; a voltage drop amount calculation unit for deducing an amount of a voltage drop; and a lookup table generation unit for generating a voltage drop correction lookup table.
