The father, Zheng Junpeng, a native of Shaanxi Province, said teachers kept reporting to him that his son, identified as Jiahao, often beat his classmates to extort for money after he entered the school in September, Longgang District police was quoted by Shanghai Daily as saying.
Zheng said he whipped his son for about half an hour when his wife was away at work that day. Then he put the boy to sleep at 11pm. He didn't notice anything abnormal until 2am when he found the body of Jiahao was turning cold. He turned on the light and saw the boy's blood seeped through his clothes.
Despite emergency treatment, the boy was pronounced dead at the hospital. Zheng was sorrowful and regretted his action.
The father had tried to discipline his son in the past, but to no avail and his patience wore out when a teacher complained again last Friday.
"The child is gone. It's meaningless to say anything," he was quoted by the daily as saying.