problem statement: The development and decline of historic cities of Iran are influenced by various internal and external factors, that the study of these factors clarifies the causes and origins of cultural and social changes. one of these historical cities is the old city of Narmashir in the east of Kerman. The old city of Narmashir has expanded from the Sasanid to the late Timurid period, based on the archaeological documents. The archaeological materials suggest that the population of the city has been fallen from the Safavid period, and it has abandoned after the Afghans attack.
purpose: The purpose is to explain the role of ecological factors in the formation, expansion and destruction of the city.
research method: Data has been collected by documentary and field methods. The research method has been analytical. So historical documents have been studied and analyzed in the "content analysis" method. Then, data are analyzed based on five variables in the Kenneth Watt's ecological theory, which includes “matter, energy, diversity, space and time”.
conclusion: Accordingly, the “space” has had the most influence in the formation and expansion of the old city of Narmashir, and the “matter, diversity and energy” have had a significant impact. “Space” while influencing the city's expansion, also played a major role in the city's departure. But, there is not much awareness about the role of matter and diversity in leaving the city, because of the lack of evidences. Also, “time” has not played much role in the development and destruction of the city. The formation, expansion and destruction of Narmashir may also be affected by non-ecological factors. But, the authors believe that the ecological factors have facilitated the three mentioned phases of the city.