Many ecotourism destinations unfortunately tend to become unsustainable and even self-destructive due to inappropriate environmental assessments. On the other hand, because of the increasing people’s willingness to tourism and relaxation, it is necessary to select and introduce new regions for tourism. To do this, the application of relevant criteria can be a profitable method. The purpose of this study is to identify nature-based tourism activities and also site selection for them in Sisangan Forest Park emphasizing plant species diversity protection. A questionnaire method was used in order to recognize demanding activities. The sample size was calculated through Cochran formula. According to this, 140 questionnaires were distributed among tourists in Sisangan Forest Park. The results showed that clouds walking, horse riding, forest hot air ballooning, night walking for seeing wildlife and photography in forest had the highest demand. In this study, the principal sources to identify criteria and indicators of demanding activities were divided into two categories: expert’s opinions and the review of other similar researches and literatures. Five main criteria including soil, slope, altitude, canopy coverage percentage and bottom coverage percentage were selected. Afterwards, with the help of Geographical Information System (GIS) abilities, suitable areas for demanding activities were determined. Finally, the maximum and minimum areas were allocated to clouds walking and photography in forest, respectively.