A pixel arrangement structure of an organic light emitting diode display, comprising: first pixels each having a center coinciding with a center of a virtual square (VS); second pixels separated from the first pixels and each having a center at a first vertex (P1) of the virtual square (VS), wherein each of the second pixels located at a first vertex (P1) of a diagonal line of the virtual square (VS) is spaced apart from a second pixel located at the other vertex (P1) of the diagonal line with a first pixel interposed therebetween; and third pixels separated from the first pixels and the second pixels , and each having a center at a second vertex (P2) neighboring the first vertex (P1) of the virtual square (VS), wherein a distance between each of the first pixels and an adjacent second pixel as well as a distance between each of the first pixels and an adjacent third pixel is a same first length (L1), wherein a distance between each of the second pixels and an adjacent third pixel is a same second length (L2) different from the first length (L1), and a distance between the two adjacent first pixels is a third length (L3) that is longer than the first length (L1) and the second length (L2), wherein the first pixels , the second pixels , and the third pixels have polygonal shapes, characterized in that the first pixels have an octagonal shape, and the second pixels have a different shape from a shape of the third pixels , each of the second pixels and the third pixels is larger in area than the first pixel , the first length (L1) is between 15 μm and 35 μm, the second length (L2) is between 20 μm and 45 μm, and the third length (L3) is between 25 μm and 65 μm. first pixels each having a center coinciding with a center of a virtual square (VS); second pixels separated from the first pixels and each having a center at a first vertex (P1) of the virtual square (VS), wherein each of the second pixels located at a first vertex (P1) of a diagonal line of the virtual square (VS) is spaced apart from a second pixel located at the other vertex (P1) of the diagonal line with a first pixel interposed therebetween; and third pixels separated from the first pixels and the second pixels , and each having a center at a second vertex (P2) neighboring the first vertex (P1) of the virtual square (VS), wherein a distance between each of the first pixels and an adjacent second pixel as well as a distance between each of the first pixels and an adjacent third pixel is a same first length (L1), wherein a distance between each of the second pixels and an adjacent third pixel is a same second length (L2) different from the first length (L1), and a distance between the two adjacent first pixels is a third length (L3) that is longer than the first length (L1) and the second length (L2), wherein the first pixels , the second pixels , and the third pixels have polygonal shapes, characterized in that the first pixels have an octagonal shape, and the second pixels have a different shape from a shape of the third pixels , each of the second pixels and the third pixels is larger in area than the first pixel , the first length (L1) is between 15 μm and 35 μm, the second length (L2) is between 20 μm and 45 μm, and the third length (L3) is between 25 μm and 65 μm. <EOS>