The researches on the urban pattern serve not only as the foundation of urban plan, urban construction and urban land utilization, but also as the basis of the urban social and economic development theory. Geographers have been studying the patterns of geographic phenomena from the general configuration of earth's surface to the urban pattern. China has made remarkable achievements in the field of urban pattern both in application and in theory since 1990. But most researchers are concentrating their studies on the mechanism of pattern change and paying less attention to characteristics of urban pattern itself, and there are no researches conducted on the objective and exact extraction of urban information. Therefore, the major purpose of this paper is to solve the problem as to how to extract urban information from remote sensing images objectively and exactly. The authors analyzed fractal characteristics of urban pattern on the basis of the above urban information. The changes of the complexity and the stability of the urban pattern can be revealed.