Isfahan Jame' mosque, one of the oldest buildings of Islamic period which is still living, has a valuable experience of traditional conservation which is the reason for the continuity of its present life. Based on the international charters, understanding this local knowledge can lead to the enrichment and enhancement of modern conservation movement in Iran, the necessity which was unfortunately received scant attention. Furthermore, nowadays conservation intervention turns to be a challenge and a controversial issue in the international and consequently national scope of conservation. Concentrating on the conservation intervention in this building and following the evidence of traditional intervention from construction time to Qajar period, this paper aims to reveal the main approach of traditional conservation intervention in Isfahan Jame’ mosque hoping to achieve traditional conservation intervention on the horizon. Through applying the grounded theory and coding of the interventions, adaptation with new conditions of each period for the continuity of its function is observed as the main approach of the conservation intervention. The main reason for the adoption of this approach is the originality of function in traditional architecture. Moreover, two secondary approaches, religious one by people and political one by government, are introduced in this mosque.