The school age of children has two meanings: ① refers to children who have reached school age. Different countries have different regulations on the academic system. Five-year-olds are required to go to school in Britain. North Korea, Romania, the United States, France, Japan, the Federal Republic of Germany and other countries all stipulate that 6-year-olds should go to school. Countries such as the Soviet Union and Yugoslavia require 7-year-old children to go to school. China's current education law stipulates that 7-year-old children should go to school. ② refers to children who meet the age of universal compulsory education. Some only refer to school-age children aged 6 or 7 to 1 1, 12; It is also said that students aged 6 to 7 to 17 and 18 are school-age children. Accordingly, the period of education in ordinary schools can be divided into three age stages: the early admission age in primary school, the middle admission age in junior high school and the late admission age in senior high school.