Abstarct: Transfer and sharing of experiences through text ads is a feature of social networking; So that nowadays tourists' behavior in destination selection is largely influenced by the written recommendations. Analysis and interpretation of some partial comments on the Internet and virtual networks are required to use scientific tools to help managers in decision making. Netnography approach combining Rough set theory can extract patterns that govern the behavior of customers. In this study, the tourists of Shiraz, Isfahan and Tehran cities in Iran who commented in TripAdvisor.com, have been studied. baxsed on ethnographic approach in network and identify important factors baxsed on results from Rosetta software. Finally, eight rules governing the behavior of tourists were extracted and analyzed.