Constitutional Revolution is one of the most important events in cnntemporary history of Iran because subsequently we observate the major changes in applying the rule. because king did not come to light of God. This article reviews the background and causes of this event based on Chalmers Johnson's theory. Johnson's theory belongs to the functionalist approach. According to this approach Society is considered as a System that each of the different components shares in maintaining the balance of total with playing a specific role. According to Johnson what has caused the revolution to take place is inconsistencies occurred due to system imbalances caused by environmental and value changes. In this article has been trying to investigate the process of environmental and value changes in society (that mismatch of them led to a revolutionary situation) based on Johnson's theory using indicators derived from this theory. The research results indicate that Value and environmental changes have taken place during the Qajar rule led to destruction the previous balance and finally occurrence of Revolution