He is known by his Semitic and Samaritan studies.

[2] Margain got his Doctor of Arts in 1988 with his thesis Les particules dans le Targum samaritain de Genèse-Exode: jalons pour une histoire de l'araméen samaritain at Université Paris III.

[3] In 1981, CNRS researchers Christian Amphoux and Jean Margain founded the Académie des Langues Anciennes (formerly called Session des Langues Bibliques), with branches in Montpellier, Saintes, Lille, Lyon and Digne.

[4] Margain was Director of research at the French National Centre for Scientific Research (CNRS) and president of the Sessions de langues bibliques (in 1988).

[5] He also was Director of studies at École Pratique des Hautes Études (EPHE),[6] and Chair of Biblical and Targoumic Philology, from 1991 to 1996.