Increasing number of rural workers heading for burgeoning cities has led to China's left-behind and migrant children totaling nearly 100 million.

The number of "left-behind children" hit 61.02 million as of 2010, accounting for 37.7 percent of rural children and 21.88 percent of the country's child population, according to a special report released by the All-China Women's Federation on Thursday.

The report, titled Research Report on Rural Left-Behind Children and Migrant Children, said the figure was 2.42 million more than that in 2005.

"Left-behind children" remain in rural homes by their migrant parents who go to work in cities far away to earn a living. The children are usually taken care of by their grandparents or other relatives.

The number of migrant children, which refers to children migrating with their parents to other places, reached 35.81 million in 2010, an increase of 41.37 percent compared with 2005, according to the report.

More than 80 percent of these migrant children are from rural areas, the report said.

Migrant children live in places where they are not registered for an average of 3.74 years, it said.

South and east China's coastal areas, such as Guangdong, Zhejiang and Jiangsu, have the biggest migrant child population. They are mainly from China's central and west provinces, which are also the main exporters of the country's migrant workers, the report said.

"Problems facing left-behind and migrant children including lack of family love, security, protection and equal education have been relieved but have not yet been resolved, and new problems keep emerging," said the report.

It said these problems will exist for a long time as China is in a key period of urbanization and the rural-urban divide will not be eliminated in a short period of time.

It suggested improving the caring service system for these children and eliminating urban political and economic discrimination against them.

The report encouraged migrant parents to take children with them for their better physical and mental development.

It also urged the government to improve relevant children's laws and reform the household registration system to ensure equal access for rural children to urban public welfare and services such as medical care, education and housing.

All figures in the report were based on the sixth China population census conducted in 2010.