The high-frigid ecotone is sensitive to climate change and often faced with shortage of water resources and environmental degradation,so quantitative study on its terrestrial ecological and hydrological change is helpful to better understand the impacts of climate. This work took the Gannan Zone as a case,based on a land model coupled with a scheme of the changes in soil freeze-thaw fronts,firstly partitioned the study area into climatological permafrost and seasonally frozen regions and explored the responses of frozen soil,water resource and carbon cycle to climate change from 1979 to 2012. The results show that climatological permafrost and seasonally frozen areas are about 15 000 km~2 and 25 000 km~2 respectively. The maximum thaw table depth in the permafrost region increased and the maximum frost table depth in the seasonally frozen region decreased. The precipitation was increasing but the warming air temperature made the evapotranspiration increased and reduced the total runoff so that the available water resource tailed off. The amplitude of decreasement was more obvious in the permafrost region. On the aspect of the ecosystem,the northern Gannan is a carbon source and the southern Gannan is a carbon sink. Climate warming promotes the plant growth,which is in favour of more carbon input from atmosphere. However,the carbon use efficiency decreases. Moreover,according to multiple linear regression analysis,it was found that in the permafrost region climate change can explain 66% of the change in NPP and 31% of the change in NEE,while in the seasonally frozen region only 45% of the change in NPP can be explained.