Abstract: With the rapid development of air transportation, congestions ofter occur. Airport congestion is the bottleneck of air transportation. Ground holding policy (GHP)is an effective way to ease airport congestion, which is used to delay some flights on the ground for some time before takeoff. And the core is slot allocation problem. In order to meet the needs of air traffic sustainable development and achieve the requirements of slot allocation scientifically,the previous research results of GHP were analyzed and summarized in this paper, focusing on concepts, properties, models and algorithms. After that, it is concluded that key issues of slot allocation are the stochastic capacity effects, the modes construction balanced between efficiency and equity and algorithms research. Finally, the tendencies of the research in the future are put forward.

Key words: air traffic control, slot allocation, ground holding policy, collaborative decision making, model, algorithm