Literature in emotional management has considered that emotions of employees may have important organizational implications. In librarianship, emotions also play an important role in affecting librarians' attitude to patrons and in turn his/her job performance. Yet the exploration of emotion has not been much studied in Taiwan's librarianship. Hence, the purpose of this study is trying to explore librarians' perception and causes of negative emotions in the library settings in Taiwan. The result indicates that librarians in Taiwan experience significant levels of negative emotions, and interpersonal relationship appears as one of the most important causes.