In this study, an attempt is to figure out the institutional changes that initiate the agricultural commodity exchange (ACE). To assess the affecting factors, new institutional economics approach has been chosen. The framework consisting of four levels of social analysis introduced by Oliver E. Williamson is used to analyze the social environment, institutional rules, institutional arrangements and finally the agency level economics (Neo-classical economics). Regarding this framework, the institutional changes that have initiated the Iranian ACE is analyzed and its constraints to further improvement are discussed.