The Patent Cooperation Treaty is another important international law in the field of intellectual property after the Paris Convention for the Protection of Industrial Property. Patent cooperation treaty is referred to as PCT. It was first put forward by the United States in 1 September, 1966, and received the response of the World Intellectual Property Organization, drafting the PCT centered on international applications. 1970 At the diplomatic conference held in Washington, D.C., representatives of 18 countries first signed the treaty text, which came into effect in June 1978. In the following 20 years, this treaty was gradually recognized by all countries in the world, especially industrialized countries, and its membership continued to expand. Before China's accession, 59 countries had joined this treaty, including all industrialized countries in the world.