Abstract: Urban system spatial structure is the basic carrier of urbanization, and the construction of scientific and reasonable urban system space structure is an important part of promoting new urbanization. To study the urban system spatial structure and scope of Guangdong Province, the methods of comprehensive evaluation with several indexes, spatial organization with voronoi and weighted voronoi diagram are used. The conclusions are drawn as follows: firstly, the polarization of cities in Guangdong province is obvious, and there is a big gap of urban comprehensive strength. Secondly, it is formed four levels of the spatial structure of urban systems, including global center city, regional center city, local center city and general city. Thirdly, the phenomenon of urban agglomeration integration exists among cities, especially the Guangzhou and Foshan, Shantou and Chaozhou. Lastly, there is an obvious dislocation between the comprehensive strength of Guangdong province and its spatial structure level. Therefore, it should ensure the strength of the low level of the cities regional positioning and functional orientation. At the same time, it should accelerate the development of the central city of weak comprehensive strength, narrow the development gap and achieve regional coordination.