To explore general regularity of NDVI change in the Karst region,and reveal the diversity of vegetable effect between semi-karst and pure-karst.Based on geology map of 1:200 000,and using SPOT VGT image data from 2000 to 2013,we carried out a comparative study on NDVI change in various lithology by the method of change slope,various coefficient and correlation analysis.The results show that it is different for various lithology to mean-NDVI,the change rate and various coefficient of NDVI,mix-NDVI decreases in the order:non-Karst>Karst>semi-Karst,various coefficient of NDVI decreased in the order:semi-Karst> typical Karst>non-Karst,and the proportion of NDVI enhance decreases in the order:typical Karst>semi-Karst>non-Karst,but the proportion of decrease is the exact contrary,the diversity of NDVI in various lithology results from the land coverage,the proportion of forest and farmland are key factories on the variation of NDVI.On short-term scale,the variation of NDVI is driven by human factor,the role of climate change is insignificant.Due to the influence of lithology,in contrast with Karst,the ecological sensitivity of semi-Karst is higher,and it is easier that the ecological environment of semi Karst is influenced by the human factor.Therefore,ecology safety should be concerned especially in semi-Karst background.