A display method of a transparent display apparatus is provided. The display method includes sensing illumination around the transparent display apparatus; determining threshold lightness using the sensed illumination; correcting image data by changing lightness and chroma of colors which are brighter than the determined threshold lightness by a first method and changing at least one of lightness and chroma of colors which are the determined threshold lightness or less by a second method; and displaying the corrected image data on the transparent display apparatus.