Under the background of global change and low-carbon development, regional natural-social system carbon budget became a hot multi- disciplinary research field in geographical, ecological, environmental, economic, and management sciences. Regional natural- social system carbon budget studies will not only offer important methods for evaluating the impact of human activities on the environment and provide theoretical basis for carbon cycle pressure assessment of the coupled natural-social system, but also has great significance for regional low- carbon development and collaborative emission reduction. Based on a regional system perspective, this article first defined regional natural- social system carbon budget, analyzed its characteristics, and presented a conceptual model of the system. Then the impacting mechanism of regional anthropogenic activities on the dualistic carbon budget of the natural-social system was discussed, and the relationship between regional natural- social system carbon budget studies at different spatial levels was analyzed. The research progress of regional natural-social system carbon budget at different spatial levels including the global, national, provincial, city, urban district and county, neighborhood, and typical industrial sector and human activity levels was summarized. Finally, the trends of regional natural-social system carbon budget research were put forward: integrated modeling and spatial differentiation of regional carbon budget, inter- regional carbon compensation, the relationship between regional carbon budget and resources and environment effects, and the comprehensive regulation and control of regional natural-social system carbon budget.