The interfaces of the Earth's critical zones are the place where organic carbon is dramatically decomposed and transformed.The dynamics and fate of organic carbon serve as an important foundation of revealing the material transportation and energy transfer in the critical zones,which is of great significance to support the ecological system.The geochemical characteristics of organic carbon in riverine system is reviewed in this study,including the research methods,sources,storage,dynamics and turnover process of organic carbon.It is suggested that the the dynamics of organic carbon in the critical zones should be studied well for understanding carbon cycling in the riverine systems.Various technical methods,short-term high-frequency observation,long-term observation research in the multi-interface with multi-time scales should be conducted in typical critical zones,in order to reveal the key factors and its mechanisms of organic carbon dynamics and processes in the riverine systems.Furthermore,the response and feedback mechanism of organic carbon cycle to global change and human activities on long-time scales should be studied.Besides,the carbon exchange between interfaces of atmosphere-plant-littersoil-river and the dynamics of organic carbon in watersheds should be further analyzed under different disturbance intensities of human activities.Understanding the impacts of environmental changes and human activities on the geochemical cycling of organic carbon in critical zones would benefit the optimization of carbon cycling model and climate change predictions.