Abstract: There exists a large gap between crop potential yield and actual yield for cultivated farmlands. Variation in crop yield from field to field is a common ubiquitous feature across agricultural landscapes. Closing yield gap plays an important role in increasing food production and ensuring food security. This study introduces the importance and necessity for closing yield gap and summarizes domestic and international research progress in yield gap analysis. The development and definition of yield gap, research method and scale, and data analysis method are documented. The application of crop growth model in yield gap research is also discussed. Finally, the main problems currently limiting yield gap analysis are advanced and research trend discussed.