Abstract: A land use conversion index was constructed based on vector data about land use types of Guangzhou in 1990, 1995, 2000, 2005, and 2010 and in virtue of buffer analysis, Lorenz curve, and other research methods. With this index, analysis was conducted on the spatial-temporal differentiation characteristics of conversions among different land use systems in Guangzhou under different levels of human influences. According to results of the study: 1) the proportion of artificial systems in Guangzhou is on a gradual increase and shows a spatial evolution characteristic of expanding from the center to the outside gradually; the proportion of natural systems in the entire system is decreasing gradually, while semi-artificial systems account for a gradually stable proportion of the entire system but the gravity center of this part begins to deviate from the urban center and expands to the periphery little by little. 2) As a whole, the functional pattern of the land use systems in Guangzhou shows a trend of changing from being dominated by ecological and production functions to a pattern where ecological, production, and living functions co-exist. 3) The mode of conversion among land use systems in Guangzhou has changed. From 1990 to 2000, conversion from semi-artificial systems with production function to artificial systems with living function prevailed, while during 2000~2010, the major conversion was from natural systems with ecological function to artificial systems with living function, with these artificial systems driving the changes in the land use function structure.

Key words: land use, Spatial-temporal differentiation, buffer zone, conversion index, Guangzhou