The four seasons system is also called the four seasons system. Bona means bookkeeping and camping in the Khitan language. It is the palace where the monarch of the Khitan Kingdom travels, that is, the temporary residence. In fact, the kingdom of Qidan has both imperial capital and five capitals. However, Emperor Qidan lived in four temples all the year round, and all government affairs were handled in temples, which was actually the political center of the Qidan Kingdom and the seat of the supreme ruler. Huang Du and Jason Wu are places where bureaucrats below the prime minister deal with government affairs, especially those of Han people, which is a major feature of political management in Qidan after the founding of the People's Republic of China.