The research was to investigate the effect of quality cognition(usage, medical information, aesthetic, safety) of the web site of the facility on customer loyalty and moderating role of trust variable. The respondents was 201 patients and caregivers. Data were collected from March 1 to 31, 2010 at C university hospital in G city. In relationship between quality cognition of facility web site and customer loyalty, the results of quality cognition on customer loyalty showed 43.1% (F=36.912) in model 1, 46.3%(F=33.454) in model 2, and 46.8%(F=18.580) in model 3. In relationship between web site quality cognition and customer loyalty, moderate effect of trust was not considerable. As results, quality is the leading fact for customer loyalty more than trust. Therefore, customer loyalty leaves its possibility of increment when facility web site is designated depending on medical information, usage and aesthetic.