Abstract:Changes of carbon pools and carbon cycles in the earth system are important factors affecting the climate system, and the mechanism of carbon budget and carbon cycle of terrestrial ecosystems is the research focus in the field of global climate change cause, trend forecasting, mitigation and adaptation countermeasure. This paper focuses on reviewing the research frontiers of regional carbon cycle and carbon budget of terrestrial ecosystems and its key scientific issues in the past few decades, and analyzing the technical requirements and development in this research field. Presently, the frontier areas and focus of research include inventory of ecosystems and regional carbon storage and their budget, a comprehensive measurement and certification of carbon sinks, network observation of carbon fluxes in terrestrial ecosystems and its driving mechanisms, controlled experiments on the responses and adaption of terrestrial ecosystems carbon cycle to climate change, and the coupling cycles of water, carbon, nitrogen processes in terrestrial ecosystem and model simulation. Simultaneously, some key scientific issues need to be resolved in this research field was suggested. In China, recent research should focus on building the three-dimensional monitoring system of integrated carbon storage and carbon budget, prospectively researching ecosystem carbon-nitrogen-water coupling cycle and its regulation, quantitatively evaluating the carbon budget and potential carbon sink of Chinese terrestrial ecosystems, and assessing the economic benefits of typical increasing carbon sink technology. These can provide reports, measurable and verifiable scientific data and technical support for greenhouse gas management, carbon trading scheme and policy system build.