Land-use change for examining the expansion of built-up and recreation, required effective techniques of spatial assessment, especially in areas with limited space such as Koh Chang island in Thailand which needed to be emphasized. The research objectives were to study land-use patterns in Koh Chang area in Trat province from 2000-2020, and study land-use change, especially the expansion of buildings and recreation area during that period, using geo-informatic technique. The study found that most of Koh Chang is forest land, up to 80% of the island, but the trend is declining. On the other hand, the area that has increased in number is built-up and recreation, which has increased from 7.22 km2 to 18.28 km2 and up to 253.19% in the past 20 years. The efficiency of geo-informatic technology can extract useful information, especially spatial data on land-use change. Therefore, it is known from which areas built-up and recreation areas are transformed in order to bring such information into a spatial database system for supporting decision-making in directing, monitoring and controlling areas for further expansion of tourism business in order not to create an impact on the environment.