“Introduction to Lifelong Learning” is a common and compulsory subject required by librarians, curators, and social education directors for certification in Japanese higher education. However, no research has been conducted on the contents of this subject. Thus, this study aims to clarify the knowledge acquired in the subject based on an analysis of index terms in textbooks. The primary results are as follows: (1) this subject is connected to adult and community education; (2) the subject contents depend on the type of certificate; (3) there are few common terms in the indices; (4) indices contain many terms specified in law as well as the names of foreign people; and (5) there are fewer words related to educational administration or learning support than to lifelong education or educational facilities.