The Nippon Medical School Central Library installed automated user entry/exit tracking system in January 2003 when library hours were extended. This report covers installation and current status.The assigned supplier was Maruzen, Inc., and equipment was the V-Line series marketed by Art, Inc., (entry/exit management system CA-10A, management software VSS-01A).Library closing was extended on January 7, 2003, from 20:00 to 21:30. The new tracking system started operation the same day.We first integrated magnetic codes of user cards (faculty ID, student nameplate, library user ID, Nippon Medical School Chiba Nursing School Library user card). Users were notified in advance that new registration would be required prior to using the new system and that registered IDs and student nameplates must be carried by users.Despite our efforts to notify users beforehand, many could not enter the library at the beginning, adversely affecting our normal library operation. It took 2 weeks before the new system ran smoothly.Total number of registered users, average daily usage by hour, and system error status are discussed.