Six boys and four girls suffered head injuries in the attack at Yangfan Primary School in Haikou, Hainan province state-run CCTV reported.
The children were taken to hospital, with two of them being treated for serious injuries that were not life- threatening.
Hong Kong-based South China Morning quoted witnesses as saying that the pupils were lined up to be released for lunch when the man approached them from outside the school gate.
Bloods stains and abandoned belongings such as shoes were seen scattered on the ground outside the school.
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Police has sealed off the area around the school.
It is not known yet what prompted the man, identified as Li, to attack the children. His motionless body was later seen lying in a lane near the school.
It was believed that he killed himself after injuring the students.
Police were investigating what they described as a "vicious criminal case brought on by extreme actions", the report said.
Numerous attacks have been carried out in the last few years by such people on primary school children. Some also set fire to moving buses causing heavy casualties.
Most of the people who carried out the attacks were described by the police as mentally disturbed.