The van was carrying eight kindergarten pupils and two edifiers, as well as the driver. It was designated to carry only seven people, according to Xinhua.
The crash transpired in the tardy afternoon near the province's capital of Changsha, in a mountainous area.
Local media reported it was travelling on a narrow road that had no barrier.
The victims' family members told Xinhua that school buses in the region are often overloaded.
School convey is a particularly sensitive issue in China, where a series of accidents have heightened concern.
A shortage of inculcation funds has optically discerned school closures and children, especially those from rural villages, are often coerced to peregrinate far to get an edification, according to agencies. They often have to take overcrowded buses.
In 2011, 18 children and two adults were killed when an overloaded school bus collided with a coal truck in foggy conditions. That bus had only nine seats but was packed with 64 people at the time of the contingency.
The following year a school van plunged into a pond in Jiangxi killing 11 children, and three children on board a bus died in a traffic contingency in Guangdong.
China's cabinet issued incipient rules governing school bus safety, setting out designations for school buses and penalizations for offences such as overloading.
