I am interested in how Linux community members build a relationship of trust. Usually, how to build a relationship of trust and its impacts depend on culture that members belong to. For example, many people believe that face-to-face communication especially drinking party after work is the most important to build a good relationship in Japan. However, it is getting difficult to have a face-to-face communication because of globalization. We must search a new approach to build a trustful relationship without face-to-face communication. Therefore, I focus on Linux community in which people work together sometimes without having face-to-face communication. I believe the reason why the success of Linux community is trustful relationship among members. I would like to survey how to build a trustful relationship in Linux community and propose a community evaluation scale using sense of trust.