Abstract: There is a large gap between crop potential and actual yields achieved in farmers’ fields. Closing this yield gap will play an important role in increasing food production, especially for China, in step with continued growth in demand, possible climatic changes, and decreased resource availability. It introduced the importance of closing the yield gap firstly, and then summarized the research progresses in yield gap analysis at home and abroad as following aspects: the development of definition, research scale and methods. Major problems at present were put forward, and the research trends were also discussed.