A method for evaluating instantaneous sector capacity based on the workload of air traffic controller(ATC)is developed.The basic characteristics of the assessed sector is described and a model to correlate the workload with the instantaneous sector capacity is developed using workload data.The correlation between the regional sector/approach sector capacity and the traffic flow organization is analyzed.Experimental results show that the instantaneous sector capacity assessment is reasonable and the instantaneous capacity is strongly correlated with the spatial and temporal distributions of the traffic flow and the sector operation mode.These results can provide an important reference for sector operation safety,capacity prediction,air traffic management,and airspace design. A method for evaluating instantaneous sector capacity based on the workload of air traffic controller (ATC) is developed. The basic characteristics of the assessed sector is described and a model to correlate the workload with the instantaneous sector capacity is developed using workload data. The correlation between the regional sector / approach sector capacity and the traffic flow organization is analyzed. Experimental results show that the instantaneous sector capacity assessment is reasonable and the instantaneous capacity is is correlated with the spatial and temporal distributions of the traffic flow and the sector operation mode. These results can provide an important reference for sector operation safety, capacity prediction, air traffic management, and airspace design.