||The objectives of this study were to assess the status of nature-based tourism resources, design and develop the database system and web application for tourism resources management in protected areas, Chiang Mai province. The data contained in the database system included tourism resource potential, recreation opportunity spectrum, and physical carrying capacity of the tourism sites in Chiang Mai’s protected areas. The tourism resource potential at 124 sites were assessed and classified into 72 conventional nature tourism (NT), 37 adventure tourism (AT), 5 ecotourism (ET), and 10 being qualified as both adventure and conventional nature tourism sites (NT/AT). The highest potential of the NT sites was identified as Keaw Mae Pan scoring 2.84 out of 3. While Mae Tang and Mae Cham – Tha Phra Sadej water rafting routes were the highest potentials for the AT (score 2.69), Doi Luang Chiang Dao for ET (2.46), and bicycling route Yod Doi Pui – Botanical Garden for the NT/AT (2.13). The recreation opportunity spectrum (ROS) offered nature closely related experiences in primitive (P), semi-primitive non motorized (SPNM), and semi-primitive motorized (SPM) totalling of 77 sites while 47 sited in semi-developed and developed areas offered less nature experience. The system was designed as relational database by System Development Life Cycle (SDLC) for the target group identified as tourism resources planners and managers. The database and web application was developed by MySQL and the available program in php script language, in that order. For the User Interface design, the web browser through internet connection was employed for database management. The database system testing regarding techniques and design earned the score 64%. While the evaluation score of user interface capability and the usefulness of the information contained in the database given by the expert in database development and the PA managers was 81% and 84%, respectively.