The influence of Internet Word-of-Mouth (IWOM) has become the hot topic of industry and academia recently, due to the significant influence of IWOM along with the rapid development of the internet and mobile terminal. In the 30 years after the start of reform and opening-up, tourism of Tibet has played a significant role in the transformation of the Tibet society. Tibet has become one of the most important tourism destinations in China and is perceived as the last "pure land" and therefore has attracted more and more tourists. However, academia has many studies on Tibet tourism resources, while little attention is paid to the behavioral research of tourist to Tibet. This paper uses Tibet as a case study to build a model from perspective of tourist to Tibet. The results indicate that: ① The model fits well, and the reliability and validity are at a good level; the model can evaluate and measure the influence of IWOM on conformity behavior of potential tourist to Tibet;② IWOM has three dimensions: credibility of Word of Mouth, proficiency of source of information and proficiency of receiver, these 3 dimensions have a significant effect on conformity of potential tourist to Tibet(γ=0.61), path coefficients of three dimensions are 0.81, 0.71, 0.58;③ Conformity behavior has two dimensions: information effect and regulation effect, these dimensions have a significant effect on purchasing Intention (γ=0.77), path coefficients of two dimensions are 0.80;④ Three dimensions of IWOM have no significant effect on purchasing Intention (γ=0.01), but conformity behavior is an intermediary between IWOM and purchasing Intention. All results above demonstrate that when information of tourism destination is unclear and potential tourists are lack of experiences, learning by compare will feature their information seeking, that is, for saving from troubles and efficiently reducing social-psychological risk, tourists generally choose the tourism destination by asking the advices and suggestions from their friends and relatives.