In 1913 he graduated from the Department of Armenian-Georgian Philology of the Faculty of Oriental Languages of St. Petersburg University, returned to Armenia and up to 1918 conducted various courses in the field of the Armenian Studies at the Gevorgian Seminary in Echmiadzin.
In 1921 he was invited to Yerevan State University, where he headed the Department of General Linguistics for many years, teaching Old Armenian, historical-comparative grammar of Armenian, Urartian, general linguistics.
He made significant contribution to the Urartology in Armenia, as well as to the investigation of the international cuneiform civilizations.
[3] John A. C. Greppin has described Ghapantsyan's work on the history of the relation of Urartu and ancient Armenia as "groundbreaking".
In 1950–1956 he was the Director of the Language Institute of the Academy of Sciences of the Armenian SSR.