The database will include DNA from the parents of abducted children. Samples will also be taken from children who are suspected of having been abducted or vagrant children with an unclear history, a notice posted on the ministry's Web site Thursday said.

China has a thriving black market in girls and women who are sold as brides, as well as babies who are abducted or bought from poor families and sold to couples who are childless or want more children.

The country also has a traditional preference for male heirs that is particularly strong in rural areas, resulting in the trafficking of boys. Some families also sell their girl babies in order to try for a boy, since the country's one-child policy limits most families to having one baby.

China's police hope to have 236 DNA laboratories sharing information about missing children by the end of May, the notice said.

In 2006, police uncovered a total of 2,500 human trafficking cases in the country, according to the Ministry of Public Security. But international groups say the number could be in the tens of thousands.