The collection, comprising 51 pieces, is among the latest 27 artefacts added to the national treasure register.
The lithophones were unearthed in 1979 and 1983 during excavations of the Binh Da archaeological site, which covers seven hectares in An Binh Commune of Bien Hoa City.
The lithophone pieces were scattered among broken ceramics and stone tools, about 55-90 centimetres below the ground.
The collection demonstrates the remarkable crafting technique of the Binh Da ancient residents, who purportedly had a rich cultural and spiritual life.
The discovery of the Binh Da lithophones is evidence that the crafting of stone musical instruments existed in Vietnam about 3,500-4,000 years ago.
Speaking at the announcement ceremony, Dong Nai Vice Chairman Nguyen Hung Son urged the provincial culture department to formulate a plan on protecting and promoting the value of the Binh Da lithophones, aligned with local tourism development.
He also called for measures to introduce the national treasures to residents, as well as domestic and foreign tourists.
