[1] Ion Ciubuc was born on 29 May 1943 in the village of Hădărăuți, at the time in Hotin County, today in Ocnița District.

He graduated from the Agricultural Institute in Odessa in 1970, obtaining the qualification of a specialist in the agrarian economy.

He initially worked as an economist at the "1 Mai" kolkhoz in the village of Hădărăuți (1960–1963), after which he satisfied his compulsory military service in the Soviet Army (1963–1966).

He is sent to a political training course, organized by the Academy of Social Sciences of the Central Committee of the Communist Party of the Soviet Union, after which he becomes an instructor of PCM in the city of Chisinau (1975–1976).

Between 1984 and 1986 he was First Deputy Chairman of the State Planning Committee (Gosplan) of Moldavian SSR.