The connections and correlations between the visual codes represent the information capability of the urban skyline. The relation and the fictional order of the structure and landscape integrity, composing the urban skyline, define the aesthetic qualities of city. Entropy, according to the information theory, is the quantification of the information amount of the coded data. Skyline coding models connected to the formal aesthetic design criteria with the developed entropy approach are to be discussed in terms of their contributions to urban design researches.