Change vector analysis and principal components analysis in NDVI time trajectories space are powerful tools to analyse the land-cover change. The length of the change vector indicates the magnitude of the change, while its direction indicates the nature of the change. This change detection method is applied to two remotely-sensed indicators of land-surface conditions, NDVI and spatial structure, in order to improve the capability to detect and categorize land-cover change. The magnitude and type of changes and the changes in spatial structure indicator are calculated by those methods in China from 1983 to 1992.