Embodiments of the present disclosure disclose a pixel structure, a mask plate, an organic electroluminescent display panel and a display device. The pixel structure comprises: a plurality of pixel units arranged in array, each pixel unit comprising four sub-pixels arranged diagonally and having the same shape and size; wherein colors of the four sub-pixels in each pixel unit are different from each other; colors of two adjacent sub-pixels in any two adjacent pixel units are same. The above pixel structure provided by embodiments of the present disclosure may enable the color of any sub-pixel in a pixel unit to be same as the colors of three sub-pixels that are located in other three pixel units adjacent to this pixel unit respectively and are symmetric with this sub-pixel relative to a same point.