Today, 52 years ago, on 22 February 1973 (Lunar Calendar 20 January 1973), the United States and China agreed to establish a contact office in both capitals. After Nixon's visit to China on 22 February 1972, the two sides reached an agreement to establish mutual contact offices in their respective capitals. For the establishment of the U.S. contact office in China, especially for the selection and reception of personnel, the Chinese government and senior leaders attach great importance. China gives the U.S. contact office in China a fairly high diplomatic status, "although there is no name for an embassy, but there is a fact of an embassy." The establishment of the U.S. contact office in China has not only very important symbolic significance, but also laid a solid foundation for the normalization of China-US relations.