Abstract: Based on the background of different spatial groups and the main functional area, this study takes 11 cities of the Pearl River-Xijiang river economic belt as the research object to evaluate the coordination degree of "four modernizations" and its spatiotemporal evolution by using comprehensive evaluation index system and exploratory spatial data analysis tools. The results show that the overall coordination level of the "four modernizations" in the Pearl River-Xijiang River economic belt tends to rise, but there is an unbalanced characteristic that the east is better than the west in the degree of integration within each group, the integration of spatiotemporal is shifted from east to west. The strength of the central cities, the synergy competency between informatization and traditional industry and the spatial division of labor are the main factors that lead to the horizontal differentiation. Strengthening policy guidance, promoting the deep integration of informatization and traditional industry, optimizing the function of land and space and playing a comparative advantage are the important ways to drive the overall improvement of the "four modernizations" coordination.

Key words: “Four Modernizations: integration, spatiotemporal pattern, comparative advantage, the Pearl River-Xijiang River economic belt