The National Science Popularization Day was launched to memorize the promulgation of the Law of the People's Republic of China on Popularization of Science and Technology, which was adopted at the 28th Meeting of the Ninth National People's Congress of China on June 29th, 2002. Since 2003, CAST has initiated National Science Popularization Day all across the nation with various themes aiming at cultivating a social environment of respecting science, paying special attention to science and using science and continuously undertaking science popularization activities with public engagement.

To implement the Law on Popularization of Science and Technology, promote the practice of the scientific concept of development and public awareness of science, and advance the process of comprehensive sustainable development of society, economy and all citizens, CAST decided in 2005 that National Science Popularization Day activities be held each year in the third weekend of September.

Activities in varied forms have been development all over the countries to enrich the initiative since its launching in 2003, which include:

--Displays and hands-on exhibits. In classes and science shows, students demonstrate the production process of the solar-energy cap and recycled paper. Families are also invited to demonstrate inventions in using air-conditioners, TV sets, refrigerators, washing machines and toilet bout in an energy-saving way. Through these activities, public awareness in saving has been enhanced. They are encouraged to contribute to the establishment of a saving society.

--Mass media. Broadcasting, TV and the Internet have been made full use in doing science popularization. Some traditional media like newspaper, blackboard, pictures are used to illustrate scientific topics, whereas video and TV programs are used to give more vivid demonstration.

--Broad scale of activities. In rural areas, science popularization takes the form of science market, courses on applied technology. In cities, activities are carried out in communities and have face-to-face communication with the local people. Some activities take even more interesting form, such as "science popularization park", which introduce exhibitions and shows into parks and have proved to be popular among the public.

--Varied target group. Scientists, science communicators and volunteers are divided into groups to go to villages, communities, schools, plants, etc. They deliver activities in forms of lectures, training courses, consultation, exhibition, video shows, performances, on-site instruction, quiz, and writing competition, etc.