In a ubiquitous computing environment, it is desirable to provide a user with information depending on a user's situation, such as time, location, user behavior, and social context. At conventions, such as academic conferences and exhibitions, where participants must register in advance, the social context of participants can be extracted from the Web using their names and affiliations without asking them many questions. In our study, we attempt to extract the social network of participants from the Web, where a node represents a participant and an edge represents the relationship of two participants. The network shows the position of each participant and some participant clusters. Furthermore, this network can be used in many services, such as finding an appropriate person to introduce or negotiate with someone, and who one should talk to in order to expand his/her network efficiently. Categories and Subject Descriptors H.4.m [Information Systems]: Miscellaneous; D.2 [Software]:...