An OLED display including a display panel, a memory, and a processing circuit is provided. The display panel includes a plurality of sub-pixels. The memory stores a compensation table. The processing circuit includes a current sensor, and a processor. The current sensor sense a current of at least one sub-pixel among said plurality of sub-pixels, and the compensation table is updated according to the sensed current. The processor receives image data and generates compensated image data based on the image data and the updated compensation table. Then the display panel displays said compensated image data.