The resistance and resilience of ecosystem services, like the biomass production, carbon storage, availability of nitrogen, and soil and water conservation to climate change and human disturbance are important not only in the context of ecosystem health but also for the livelihood of people who rely on it, especially in arid and semi-arid regions where ecosystem are vulnerable and sensitive to alterations. To maintain a sustainable ecosystem and enact the effective management policies, the decertified and degraded should be restored based on fully understanding the underlying mechanism of degradation and restoration. Involving this focus, my research is mainly conducted in two aspects. One is the ecosystem carbon and water fluxes, biomass, net mineralization responses to climate warming in a semi-arid grassland on the Qinghai-Tibet Plateau (QTP) through field manipulative experiment. To complete this study, knowledge of field experimental design and statistical analysis is developed in addition to the skillful operation of Li-Cor 6400, 8100. Another is the investigation of the relative contribution of human activities and climate change to the land desertification in Northern China. The study employs statistical modelings like structural equation modeling and boosted regression tree. Moreover, preparation of input data requires the knowledge of remoting sensing and GIS.