Cochrane Library in a medical center in Kaohsiung Taiwan. Methods: The data collected Cochrane Library usage and UpToDate usage in a medical center censored by the electric automatic censor system in a hospital library from 2006 Jan to 2008 Dec. Results: The Cochrane Library usage increased significantly (r2 = 0.280, P = 0.001) in this hospital, and the total usage was 6,211 in the 3 years period. The peak usage in 2006 was in Nov (n = 139) that we have an evidence based practice contest on Dec 30th 2006. The peak usage in 2007 was in Dec (n = 289) that a contest on Jan 26th 2008. The 2 highest hit in 2008 were in Jun 2008 (n = 415) and Oct 2008 (n = 1,030) that there were 2 potential teacher training courses on the same months. MD consult database also had the same trend hit as the Cochrane Library hit and increased usage in the 3 years period (r2 = 0.604, P&0.001). The total usage was 23,138 in the 3 years period. We did not find the same usage variation of UpToDate database (r2 = 0.001, P = 0.873) in the same period in the hospital. The total usage of UpToDate was 63,943 in the 3 years period. The usage occupation is doctors (55.0%), nurses (32.7), technician (9.9%), and administrators (2.4%) in Cochrane Library. The usage of UpToDate is different from Cochrane Library usage as in doctor (89.3%), nurses (5.3), technician (5.0%), and administrators (0.4%). Conclusions: The usage of Cochrane Library is increasing year by year but is still not as popular as UpToDate in our hospital except in teaching courses or contests motivation. The usage of Cochrane Library is about 1/10 of the usage of UpToDate in a medical center.