This paper, based on the general survey data of the tertiary sector, focused on the development of the information intensive services and their impacts on the urban spatial structure of Guangzhou since the middle of 1980s. The development levels of information intensive services, including the general and internal levels, were initially analysed, which showed that the information intensive services of Guangzhou had higher development level than those of Guangdong Province and the whole country, and contributed greatly to the rapid development of the whole services. Then, the attention was turned to the analysis of the spatial development characteristics and reasons of information intensive services. Three characteristics were identified: the information intensive services had a multi cluster spatial pattern, there existed some dominant trades in the neighborhoods with relatively developed information intensive services, and the development centre of the information intensive services shifted obviously northwards. Many factors influenced the formation of the current spatial pattern of information intensive services, including historical, policy, economic, urban planning and construction factors and so on, but policy could be ranked the most important factor. Thirdly, the impacts of the development of information intensive services on the spatial structure of the city was examined. The results showed that the development of the information intensive services caused 1)the spatial replacement of urban function areas, 2)the upgrading and change of CBD functions and morphology, and the appearance of twin centre urban spatial structure, and 3)formation of the new growth core of the city with the development of technopole in Guangzhou. Finally a conclusion was drawn.