The incident took place shortly after midnight in Changsha, capital of Hunan province, police said in a statement.
"A motor vehicle hit pedestrians," it said, adding that eight people had died in the tragedy and another five had been injured, at least some of whom had been hospitalized.
A 55-year-old suspect living in the area has been detained and the investigation is ongoing, the statement said.
Road accidents are common in China due to a lack of strict safety controls.
Assaults with vehicles have also occurred, but police have not indicated whether this was a purposeful act.