A pixel arrangement structure includes a plurality of pixel groups that are periodically arranged. Each pixel group includes four pixels, a first pixel (310) and a second pixel (320) are arranged in a same row, a third pixel (330) and a fourth pixel (340) are arranged in adjacent another row, the first pixel (310) and the third pixel (330) are arranged in a same column, and the second pixel (320) and the fourth pixel (340) are arranged in adjacent another column. An arrangement of sub-pixels in the first pixel (310) is different from an arrangement of sub-pixels in the second pixel (320), an arrangement of sub-pixels in the third pixel (330) is same as the arrangement of the sub-pixels in the second pixel (320), and an arrangement of sub-pixels in the fourth pixel (340) is same as the arrangement of the sub-pixels in the first pixel (310). The pixel arrangement structure allows the opening area of the metal mask for manufacturing the pixel arrangement structure to be larger, and therefore the aperture ratio is increased and the brightness, service life and image definition of the AMOLED product are improved. An organic light emitting device, a display device and a mask are also provided.