There are three types of imperial examinations in the Song Dynasty: regular examinations, system examinations and martial examinations. There is a "bright number" and a "dark number" in the six theory. The difference between the two lies in whether or not the statute system and the number of allusions are cited in the title. "Dark number" are extremely difficult and need to be able to cite the context; "bright number" also require a comprehensive answer, which is not simple. This article tries to make a brief analysis of this type of topic, which is helpful to understand the ancient imperial examination system and imperial examination culture.