This is the moment a boy bravely chases after his grandma, trying to rescue her as she unintentionally reverses out of control and at speed while exiting the drive.

Surveillance cameras captured the incident outside a rural home in Suzhou, in Anhui, China, on Monday evening, March 11.

In the video, the little boy appears to be about to get on his children's trike that was parked next to his grandma's car.

But the old woman, who was sitting behind the wheel of her vehicle and was getting ready to leave, suddenly appears to step on the accelerator as she begins to reverse, with the car darting backwards down the drive at speed.

The woman's six-year-old grandson dropped his bike and began chasing after the vehicle, attempting to save her.

He could be heard shouting with tears in his voice: 'Brake!'

His yelling eventually prompted onlookers to come to her aid and they were able to rescue her.

The child's mother later said: 'Watching the surveillance footage, I was anxious, wishing I could press the pause button at that moment, so the car would stop right there.

'Thankfully, everyone is safe.'