Considering ecotourism as a spatial pattern is common in our contemporary world. From the bioenvironmental point of view, ecotourism maintains the environment and, from the economical viewpoint, it leads to economic dynamism in the local community by providing employment and income. Thus, recognizing the potentials and approaches toward developing natural tourism in different geographical regions is extremely significant. In this regard, the present study deals with assessment of the natural tourism potential of the Sistan area. This research aims at assessing the attractiveness of the ecotourism sites in Sistan, recognizing its ecotourism spatial development potentials, and determining approaches for reinforcing ecotourism at the regional level. This study employs a descriptive, analytical and survey method using 14 indexes, using the "cluster analysis" model. The findings show that the Chahnimeh natural wells of Sistan, Hamoon Lake and Khaje Mountain are the most attractive ones on the basis of attracting ecotourism because of enjoying high potentials (highly attractive). Kuhak dam, the forest Park of Jazinak, Hirmand River, Sistan dam and Zahak dam are all at the second level (middle attractive) because of the lack of cultural capacities, residential facilities, tasty and drinkable water. Finally, the desert landscape of Sistan is at the lowest level (low attractive) due to a lack of natural resources, limited environmental attractiveness, shortage of recreational equipment and the low level of accessibility and security. Therefore, considering developing the potentials of each area and providing appropriate facilities and equipment, the priority of spatial development can be put as low attractive, middle attractive and high attractive, respectively.