The school children, all from the same kindergarten school in Gansu province, Wuwei city, suffered severe fever, vomiting and stomach ache after eating porridge and buns for breakfast at the school on Wednesday, reports say.
In preliminary investigations, the food poisoning was found to be a result of eating pork infected with diarrhea-inducing bacteria.
Chinese authorities are continuing to investigate the cause of the poisoning while the children were being treated in four different hospitals.
According to reports, most of the children had been allowed to return home by mid-afternoon Saturday.
Unsafe food handling practices often cause mass food poisoning cases in China, reports say.
