The crash happened around 9 a.m. in a rural area of Guixi City when the van, carrying 15 kindergarteners and a teacher, crashed into a roadside pond, Xinhua reported.
Officials said the pond was 10 to 13 feet deep.
Three children died at the scene while eight died after being transported to a local hospital, local authorities said. The four children who were injured are in stable condition.
The driver of the van was detained for questioning and an investigation has been launched into the cause of the accident, police said.