The Convention on international exhibitions defines the purpose of hosting the world exposition: the world exposition is a display activity, no matter what its name is, its purpose is to educate the public.

It can show the means of human beings to meet the needs of civilization, show the progress made by human beings in one or more fields, or look forward to the future.

The Convention on international exhibitions clearly stipulates the classification of World Expo, the cycle and the rights and obligations of exhibitors and organizers.

The Executive Office of the International Exhibition Convention, the International Exhibition Bureau and its working functions, has also been clearly defined.

At the same time, the Convention on international exhibitions also stipulates that the exhibitors of the world's less developed countries are obliged to give free or preferential treatment in respect of exhibitors' fees and give certain subsidies to some underdeveloped countries.

For example, in addition to the free venue, subsidies for booth design, construction, layout and exhibitors' costs can be granted to some economically difficult countries to join World Expo.

With the development of the international community and the different problems that have emerged in World Expo, the Convention on international exhibitions has been revised and revised many times in May 10, 1948, November 16, 1966, November 30, 1972, June 24, 1982 and May 1988 31, and has been supplemented by the amendment so that the Convention on International exhibitions will be perfected continuously, and the classification and standards of the world fairs will continue to be reasonable and scientific.