The boy rolled on the floor, got up and started running towards the vehicle.
However, the vehicle was driving off without him.
Stunned, the boy stood looking on as if unsure about what to do next.
One of the passengers in the car behind identified by his surname Jiang, got out of his vehicle, picked the child up, and returned him to his grandfather.
The grandfather explained that the boot door had been damaged in a previous collision and would occasionally fly open on its own.
On the day of the incident, the young boy climbed over the back seat and fell out of the vehicle when the door opened.
He was extremely grateful to find that his grandson was safe, and said the consequences could have been disastrous.
Fortunately the child was not injured during the incident.
Child safety seats are not common in China, and according to People's Daily, and child mortality rate from traffic accidents in the country is extremely high because of this.