Zhao Jianzhi, 44, from Shangpinglong village in Yunnan Province, was detained for poisoning 32 children, who showed symptoms of food poisoning on March 19 in Jiajia Kindergarten in Pinglong Village.
Two of them died, local police said in a statement.
The kindergarten had a total of 76 students, all of whom were sent to hospital for observation.
According to the statement, Zhao, former security guard at the kindergarten, committed the crime upset over being forced to move out of her guard's room there.