The Hiyoshi Media Center of the Keio University Library holds a collection of both Western and Japanese early books. Although the size of this collection may not be large, it contains historically significant copies. However, there has been no systematic catalogue nor active use of this collection. The present writer has therefore organized an exhibition of the rare books housed in the Hiyoshi Media Center on the occasion of the Hiyoshi Research Portfolio (HRP), an annual event for introducing research activities at Hiyoshi campus to the public. This paper is a reprint (with some revisions) of the catalogue prepared for the exhibition held at HRP 008. In total sixteen editions of Western old books were selected for the display, ranging from 16 th-century Continental books to 1 7th-century English books, including Jean de Coras's Arrest memorable, dv Parlement de Tolose (Lyon, 1561), Louis Maimbourg's Histoire de Calvinisme par Monsieur Maimbourg (Paris, 1682), William Camden's Annales (London, 1625) and Comedies and Tragedies Written by Francis Beavmont and John Fletcher Gentlemen (London, 1647).