The travel and tourism industry is flourishing worldwide. It is vital for tourism-related supplier and markers to understand tourist traits in order to target tourism consumers and further assist decision makings. With the development of social networks, tourists published large quantities of travel experiences on social networks where they disclose their traits explicitly and implicitly. In this paper, we design a methodology for tourism traits analysis based on social networks, which includes three components: tourist demographic analysis, tourist social influences analysis, and tourist behavior analysis. Sina Weibo based Chinese tourists in Switzerland analysis is as a case study for our methodology, and different findings are obtained. Those findings are beneficial to tourism-related suppliers and markers to make valuable strategies. And our proposed methodology could be applied to analyze tourist traits in any social network platform.