Literature related to energy flow in the CNKI and Science Direct databases was adopted as our data source. Using co-word analysis,multi-dimensional scaling analysis and strategic coordinate analysis we analyzed the internal structure of every field of energy flow research and the interaction between various areas. Results show that the study of energy flow in China can be divided into four categories, taking sustainable development of ecosystems as the research core in which material flow and energy value methods are widely used. The most mature research category is focused on the energy flow among food chains or food net systems to better understand biomass and productivity using quantitative analysis. The other three categories are microbial decomposition, ecological community structure and new energy. The study of energy flow research outside China can be divided into five categories with a clear research core composed of energy consumption, energy conservation and energy indicators. The most mature research category is life cycle assessment exploring renewable energy and carbon emissions. The second most mature category is the environmental impact of economic development,especially the industry and manufacturing sectors focused on model analysis. The other three categories are the direction of climate change, energy measurement indicators and China. Comparing research between China and other nations, it is clear that Chinese research on energy flow is mainly focused on ecological dimension, and international research explores energy flow on economic and social dimensions. In the future, the categories of climate change, energy measurement indicators and China should be strengthened, and more attention should be paid to the study of China s economic and industrial systems from an energy flow perspective.