Substitute teachers refer to temporary teachers who have no career establishment in public schools. 1984 was called private teachers before the end, and the temporary teachers who had been teaching before were basically full-time or retired. Starting from 1985, in order to improve the quality of teachers in basic education, the Ministry of Education banned the appearance of private teachers nationwide. However, many remote and poor mountainous areas are unable to recruit public teachers or public teachers are unwilling to go because of economic difficulties. These vacancies still need temporary teachers to fill. They are called "substitute teachers".