Tourism in Iran has undergone many ups and downs in line with political changes. Reviewing the upper documents and plans show how important is tourism sustainable development in Iran. In this research, sustainable development of tourism in Five-Year Economic, Social and Cultural Development Plans of Iran has been studied. By applying the grounded theory in the form of a model of causative factors, predisposing factors, intermediary factors, strategies and development implications, sustainable tourism has provided a general picture of these plans. From the above mentioned plans, 80 propositions were selected using the theoretical sampling method and 374 initial concepts (open source) were identified by coding them. Then, by considering the content sharing of open source, 47 sub categories and 18 major categories were produced. The contribution of this research, compared with other previous studies, is identification of a process sustainable tourism development model for Iran along with the causal conditions, context conditions, intervening conditions, strategies and consequences. According to the model, the main categories are: causal conditions (environmental concerns and geopolitical position of Iran), the core phenomenon (sustainable development of tourism), context conditions (tourism stakeholders participation, education and research), intervening conditions (tourism sense of place, financial management, safety and security, modern technology and good governance), strategies (tourism management and planning, marketing, green management, carrying capacity, sustainable transport management, control and supervision) and consequences (cultural richness, conservation of tourism resources and well-being and quality of locals life) have been linked in a paradigmatic framework.