Three children among the dead in the attack, which took place in Lianjiang in Guangdong province.
A spokeswoman for the city government said the attack took place in Lianjiang in Guangdong province on Monday.
“The victims include one teacher, two parents and three students… and one suspect has been arrested,” she told the AFP news agency.
The BBC also reported the incident, citing local police who said the attack took place at 7.40am (23:40 GMT on Sunday), and the suspect – a 25-year-old man with the family name Wu – was arrested 20 minutes later.
Police have classified the case as “intentional assault”, the report added.
China has seen a number of stabbing attacks in schools in recent years.
In August 2022, three people were killed after an attack in southern Jiangxi province that also targeted a nursery school.
The incident was the top-trending discussion on the Weibo, social media platform, with 130 million views as of 12.20pm (04:20 GMT).