Several others were injured, including one who is in critical condition.
The bus appears to have rammed into the students and parents as they were standing outside the gates of a school in Tai’an city.
The driver "lost control" of the vehicle, state media report, and was taken into custody as police investigate the cause of the incident. It is unclear if the incident was intentional.
"So far, a total of 11 people have died (including six parents and five students)," Chinese state media confirmed, after the bus struck a group of parents and children on the side of the road.
Twelve others are in stable condition.
Images and videos of the incident are being shared on social media, showing people appearing to be trapped under the vehicle.
This comes just days after students returned to school for the start of the new academic year.
Deadly traffic accidents are a frequent occurrence in China. In July this year, police said a vehicle crashed into a group of pedestrians in the central city of Changsha, killing eight people and injuring several others.
Ali Abbas Ahmadi