Since September 14, 2006, China and Cambodia have mutually exempted visas for holders of diplomatic and official passports. Visa is a measure taken by a sovereign country to safeguard its sovereignty, dignity, security and interests. With the development of international trade and international political relations, and the prosperity of tourism, the visa regulations of the country tend to be simplified. At the same time, it is also based on the principle of whether the treatment given by the country to its own nationals is equal and reciprocal, and the same preference and convenience are given to the exchanges between the nationals of the two countries. Domestic visas are business visas (E visas). After entering the country, they can apply for a half-year or one-year long-term residence visa to the Cambodian Immigration office through a local travel agency. Holding a tourist visa (T visa), the type of visa cannot be changed after entry.