Agro-ecosystem is one of the terrestrial ecosystems under the intensive control and interference by human activities,the estimation on carbon source or sink of agro-ecosystem has become a study focus in the field of global carbon cycle studies.Direct and continuous long-term measurements of carbon fluxes over grassland ecosystem have become possible due to the improvement of eddy covariance method.This paper summarizes the research progresses of carbon flux over agro-ecosystem based on the eddy covariance method in China,and gives emphasis to the research results on the temporal variation characteristics,driving mechanism and model simulation of carbon flux over agro-ecosystem.Based on the research,the paper also offers some suggestions on the study of carbon flux over agro-ecosystem in China,and points out that long-term observation and study,multi-factor cooperative function,model development and scaling,data quality control and assessment should be the key research directions.