Background: RFID/USN develops information system for anytime, anywhere, anybody- access Electronic Medical Records (EMR). The goal is to study of patient behavior according to develop RFID/USN-based information system for hospital environment. Methods: This paper presents the use of RFID in Hospital Information System, first, unable to recognize, second , able to recognize as a pursuit of place and suppose the time of medical examination. A retrospective analysis of 235 RFID monitoring results, from ENT ambulatory 4 clinics of Seoul National University Hospital, were extracted by reader program and monitoring of RFID tag. Results: Number of subjects are 235 cases . Number of cases unable to recognize are 39/235. Number of cases able to recognize as a pursuit of place, are 196/235. some of them , certain cases are 47/235. In addition, Number of cases able to suppose the time of medical examination are 31/235. A RFID detection for sensing reader of this study has been put into representing "place" and "spending time" of patients for medical history taking and examination. Conclusion: Through the RFID of detection for specific place and spending time of medical examination, RFID/USN develops information system progressing in the EMR of hospital system and might be realized. RFID/USN networking was implemented, allowing special view on data to generate tentative patient behavior in ubiquitous hospital information system.