According to the 'Daily Express', the unnamed girl was brought to a hospital in Changchun when she was more than eight months pregnant, and two days later she gave birth by Caesarean section to a boy weighing six pounds.
Despite the girl's age and potential for medical complications, both the mother and baby are doing well, the British tabloid said.
The family has apparently refused to discuss the circumstances of the pregnancy but had reported it to police.
Some reports suggested the girl had been raped. In fact, in China, sex with a child under the age of fourteen is an automatic rape conviction. Police were last night said to be trying to establish who the father was.
Young pregnancies are said to be on the rise in China. About 30 per cent of recent abortions in a Shanghai hospital were carried out on schoolgirls, the report said.
A 12-year-old girl is thought have become Britain's youngest ever mother when she gave birth in 2006.