The paper aims to develop and validate an internet literacy scale for high school students. The study emphasizes the importance of internet literacy, especially for adolescents who need sufficient internet literacy to gain self-development and live their whole lives in this information age. The study has recruited 744 high school students and provided a validated scale consisting of thirty items in eight dimensions: (1) self-management, (2) self-image construction, (3) damage control, (4) information processing, (5) critical thinking, (6) cooperation, (7) consciousness of morality, and (8) consciousness of security. The current developed scale can reflect the latest, abundant meaning of internet literacy. This study fulfills the need to build up a validated, comprehensive internet literacy scale for adolescents such as high school students. The study also suggests potential applications of the scale in the pedagogical context.