Taking two typical rivers in high mountains and steep gorge areas as example,this paper analyzes the spetiotemporal variability of the eco-hydrological characteristics and the driving forces leading to changes.Firstly,based on the species-environmental data processing,this paper adopts canonical correspondence analysis(CCA)method to identify the environmental factors influencing the distribu- tion of river bank vegetation.Secondly,this study uses the ecological diversity Index to represent the spatiotemporel variability of ecological characteristics.Thirdly,this paper uses the multiple correlation method to analyze the relationship between the hydrological factors and meteorological factors,and to identify the key factors leading to the hydrological regime changes.At last,based on the analysis of basin water quality data,this paper analyzes the regularity of spatiotemporal variability and its driving forces.By the systematic analysis on the outcome,we could get that the spatiotemporel distribution of eco-hydrological characteristics shows the regular changes from the upstream to downstream(from the north to the south),and the spatiotemporal variability of eco-hydrological characteristics is typical from the east to the west.Altitude,aspect and water distribution are the primary natural driving forces leading to the spatiotemporel variability of eco-hydrological characteristics;and exploitation and op- eration of hydroelectric power station,construction of road on the river bank,and basin land utilization are the main human driving forces. Taking two typical rivers in high mountains and steep gorge areas as example, this paper analyzes the spetiotemporal variability of the eco-hydrological characteristics and the driving forces leading to changes. Firstly, based on the species-environmental data processing, this paper canonical correspondence analysis (CCA) method to identify the environmental factors influencing the distribu tion of river bank vegetation. Second, this study uses the ecological diversity Index to represent the spatiotemporel variability of ecological characteristics. Thirdly, this paper uses the multiple correlation method to analyze the relationship between the hydrological factors and meteorological factors, and to identify the key factors leading to the hydrological regime changes. At last, based on the analysis of basin water quality data, this paper analyzes the regularity of spatiotemporal variability and its driving forces. By the systematic analysis on the outcome, we could get that the spatiotemporel distribution of eco-hydrological characteristics shows the regular changes from the upstream to downstream (from the north to the south), and the spatiotemporal variability of eco-hydrological characteristics is typical from the east to the west. Altitude, aspect and water distribution are the primary natural driving forces leading to the spatiotemporel variability of eco-hydrological characteristics; and exploitation and op- eration of hydroelectric power station, construction of road on the river bank, and basin land utilization are the main human driving forces.