Under Chinese law, relics are property of the government and the father submitted it to his county's Cultural Relics Bureau last week, the agency reported.
Historians say the 26-centimeter, or 10-inch, yellow-brown sword could date back 3,000 years to the Shang and Zhou dynasties, the news outlet reported.
The bronze sword found by a Chinese boy could be as old as 3,000 years
There were few swords made during that period, so experts say they believe the ancient weapon was owned by a person of wealth and status.
"The short sword seems a status symbol of a civil official. It has both decorative and practical functions, but is not in the shape of sword for military officers," local historian Lyu Zhiwei told Xinhua.
The agency reported that the sword might have been dug up due to a series of recent dredging projects in the river.