Abstract:    Over the past 40 years since the reform and opening up, China′s economy has become more and more closely linked to the world economy. Ports have become a window to represent the national economic development, urban economic growth and opening up. They are important strategic resources for the national and regional development. By 2022, China has occupied eight of the top ten ports in the world with the largest throughput, and China has become a recognized port power in the world. However, there are still many problems in China′s ports, such as serious homogenization and disorderly competition, low utilization rate of port resources and unreasonable functional allocation, which lead to low port efficiency and slow down the pace of building a world-class port in China.With the rapid development of the global economy, and the continuous strengthening of the port collection and distribution conditions and loading and unloading capacity brought by technological innovation, the radiation radius of the port service hinterland is constantly expanding, and the process of the port development to large-scale and specialization is constantly accelerating. In order to improve the scale effect and competitiveness of port groups, all the major ports around the world have gradually started the practice process of port integration. Under this background, how to scientifically evaluate the development efficiency of China′s port groups under the integrated operation mode, identify the driving factors that affect the development of port groups, and explore the resource intensive optimization and governance strategies of regional port groups suitable for the "integrated operation" mode is a scientific issues worthy of academic study, which is of great significance to build a world-class port in China.Based on the scientific connotation of regional port group efficiency under the integration operation mode, this paper takes "regional port group" as a whole as a decision-making unit, divides the operation process of regional port group into production stage and hinterland service stage from micro and macro levels, and measures the total efficiency and staged efficiency of nine regional port groups in China from 2010 to 2019 by using the super-efficiency network SBM model considering the unexpected output. In addition, we apply the standard deviation ellipse model and Tobit model to further discuss the spatial evolution of the regional port group efficiency and its influencing factors, and put forward some countermeasures and suggestions for the efficient development of regional port groups. It is found that, from the time dimension, the total efficiency, production efficiency and hinterland service efficiency of China′s port groups all showed an upward trend during the evaluation period, and the hinterland service efficiency contributed a lot to the total efficiency. From the perspective of spatial dimension, the efficiency of port groups in southern China is generally higher than that in northern China. In the later period of the study, the focus of efficiency shifted from south to north, and the imbalance of regional development improved. The age, location advantage, industrial structure and hinterland collection and distribution capacity of the port can promote the improvement of the regional port groups efficiency, while the increase of port infrastructure can inhibit the improvement of regional port groups efficiency.The above conclusions have important policy implications for promoting the process of China′s port integration and realizing the goal of world-class ports construction. First, China should optimize resource allocation, promote the rational and efficient utilization of port resources, and improve the production efficiency of port groups. Second, it should strengthen exchanges and cooperation, narrow the development gap between the northern and southern ports, and realize balanced regional development. Third, it should also promote technology upgrading, build an intelligent collecting and dispatching system, promote multi-level and high-quality services for regional ports, and continuously improve the efficiency of regional port groups.

Key words: port integration, regional port group efficiency, network SBM-DEA, standard deviation ellipse, Tobit model