The present study designed, developed and operated a web portal to support remote island for sightseeing and disaster management. The web portal is developed adopting web-geographic information systems (Web-GIS), and connecting with external Social Networking Services (SNS) and the watch over system. The web portal is operated in Tashirojima Island that is a small island in Ishinomaki City, Miyagi Prefecture in the eastern part of Japan.The web portal enables to visualize the necessary information concerning sightseeing on the digital maps of Web-GIS. Using Twitter, it is also possible for users to share a variety of information transmitted from an islander in real time. Additionally, using the watch over system, users can usually watch over islanders from the outside of Tashirojima Island. When natural disasters suddenly occur, users can notice the serious situations, and rescue teams to quickly rescue islanders, and support for recovery and reconstruction of Tashirojima Island.The web portal has been operated since February 22 in 2019, and it has been continuously accessed from the inside and outside of Japan until now. Additionally, users access to the web portal using various types of information terminals. Therefore, the further use of each function can be expected by the continuous operation of the web portal.