K 12 or K- 12 is the abbreviation from kindergarten to twelfth grade, which means from kindergarten (generally 5-6 years old) to twelfth grade (generally 17- 18 years old). These two eras are the United States, Australia and Australia.

K 12 is a special term for education. The United States, Canada and other North American countries adopt free education from kindergarten to grade 12, which can also be used as a general term for the basic education stage. 1998, this concept was introduced into China, and "K 12 China Primary and Secondary Education and Teaching Network" was opened, which opened the precedent of K 12 online education. Compared with the foreign K 12 education system which has been perfected after years of reform, China's K 12 education system is not perfect, but there is still a lot of room for development. This paper will briefly describe the education system of K 12 in China and the United States, and compare the education between China and the United States, so as to clarify the enlightenment of American education to China education.