||In this paper, we propose a social navigation system called "Aikuchi", which enables users to mark a string on a Web page and share it with other users in a community. If users mark a string on their Web browser using their mouse cursor, Aikuchi recommends links to other Web pages based on recommendation algorithms. When a user clicks a recommended link, Aikuchi highlights a marked string as link anchor. We offered the system as part of a conference support system. According to the analysis of user logs, users preferred Web page recommendations based on strings marked by other users to those based on simirality-based recommendation and collaborative filtering. As a result, we think that marked strings are appropriate for social navigation.