A transparent active matrix organic light emitting diode AMOLED display based on a bottom emission structure, which is best for largesized OLED displays, has been fabricated. The transparent AMOLED display shows an image only to its bottom side, and background images can be seen through the transmissive windows. Pixel layout of the conventional bottom emission structure has been redesigned to merge transmissive openings to a single window per each pixel for higher transmissivity. A prototype of the transparent AMOLED display demonstrated 27% transmissivity and 100% NTSC color gamut.