Abstract: Based on the technology of GIS and RS,the RS image of Landsat 7ETM in 2004 was used as the main data source.In the paper,with the new district of Lanzhou City as an example,the ecological security was evaluated by means of GIS spatial analysis functions and the entropy weight method,and countermeasures were put forward.Results show that the distribution of ecological security was uneven in Lanzhou and the differences were significant.Ecological security indexes were increased from new center area to the surrounding areas.The suggestion was that ecological planning and construction were constructed in the areas with lower indexes of ecological security,ecological restoration were constructed in the areas with higher indexes.

Key words: ecological security evaluation, GIS;RS, new district of Lanzhou