The Kazhdumi Formation is a significant source of hydrocarbon in the south of Iran, which has produced abundant oil in most onshore oil fields. The hydrocarbon potential of this formation is investigated in 20 fields in the Persian Gulf. total organic carbon contents range from 0.3 to 6% with an average of 1.55%. Most samples have kerogen types II, II/III, and III, which are at the immature to early mature stage. Burial history and thermal maturity investigation show that the Kazhdumi Formation at the Persian Gulf area, in contrast to the Zagros Basin, thermally immature, and poor in terms of hydrocarbon generation.