Abstract: To reveal the impact of land use change in urban fringe in karst region on ecological risk, choosing 18 towns in the 2 lakes and 1 reservoir area in Guiyang, Guizhou Province and based on the land use information in this region from MSS imagine in 1973, TM imagine in 1993, ETM imagine in 2001 and ALOS imagine in 2010, the ecological risk assessment model of the land use was built in terms of the risk sources, resistance stability of risk receptor, and further the temporal and spatial variation of risk characteristics in the region were quantitatively assessed by taking the township administrative divisions as basic unit. The research results showed that: ① The regional ecological risk index for the past 40 years generally increased firstly and then decreased, with increment ratio of 279.06%, 21.90% in 2 periods of 1973~1993 and 1993~2001, and with a decrement ratio of 115.52% in period of 2001~2010. Except for the continuous increment of land use risk index due to land fragmentation, the other indices of ecological risk were improved after deterioration. ② The spatial difference of the ecological risk status in the region was notable, the dual influence of ecological restoration and urban expansion had resulted in a spatial differentiation of ecological risk, especially the ecological risk in the built-up areas of Nanming District, Yunyan District and the townships of Hongfenghu, Xiayun increased and then remained basically unchanged, however the risks of the area around the built areas such as townships of Jiuan, Shiban, Jinzhu etc. decreased gradually.