Their care and safety is mutual responsibility of families, government and society as a whole.
The central government intends to improve care systems for children left-behind in rural areas by migrant worker parents, a high-level government meeting pledged on Wednesday.
A system will be set up to serve such children by reporting on them, intervening and offering assistance as needed, all to keep them from falling prey to criminal activity.
The decisions were made at an executive meeting of the State Council presided over by Premier Li Keqiang.
The meeting also discussed measures to reduce the number of left-behind children by encouraging migrant workers to permanently move to cities or work near their rural homes.
A statement issued after the meeting said that "caring for and protecting millions of children left behind in rural areas, and allowing them to grow safely and in good health is the mutual responsibility of families, government and the society as a whole".
Each party, it said, including the local government, village committee and school, must carry out its duties. Charity and social organisations were encouraged to participate to improve the system.
China has about 60 million left-behind children.
In recent years, a number of tragedies have called attention to their plight.
Last year in Bijie, Guizhou province, four children of absent migrant workers committed suicide at home. They were aged 5 to 13.
Also in Bijie last year, a 15-year-old girl and her 13-year-old brother were killed at home. Police found that the girl had been sexually assaulted before she was murdered. Their parents were migrant workers away from home.
In 2014, 10 villagers were imprisoned for repeatedly raping and sexually assaulting a left-behind 13-year-old girl in Guangxi province.