The CCTV footage shows the man standing beneath the window ledge, waiting with his arms out, until the young child finally comes crashing down.
The man, identified as Mr Li, was one of several people in Xiaolan Town, Zhongshan City who spotted the baby on the ledge, which Li thinks may have climbed to while searching for its mother.
"Some people put down cardboard to avoid serious injuries to the baby if I fail to catch him," Mr Li told a local news station. "I didn't think too much at the time. I was just afraid of failing to catch him. It was nothing but human instinct to do so."
At the end of the video, Li and another man later hand the unharmed baby to his grateful mother.