Smart city has been a popular research agenda for the past years and have been trying to provide various new services to aid and improve life quality of the public. In this study, the authors utilize floating population analysis to provide 'floating population map', which can better reflect real movement of publics living in Songdo Incheon area. By implementing floating population analysis which contains more information than traditional census population such as hourly based population and weekly based population, the authors used Getis Ord Gi∗ algorithm and STSS (Space Time Scan Statistics) algorithm to conduct case studies and provided with key scenario which can be implemented into developing smart cities around the world. By using floating population older than 60 years old, new sights for elderly care facilities were derived, also by using floating population data of night time movement, areas which require more security service in the night time were derived. These new insights derived from floating population data could be used as key information for emerging smart cities.