This project aims at promoting the idea and implementation of digital citizenship education to Hong Kong schools and supporting in-serve teachers in professional development. Twenty teacher participants from seven local secondary schools joined the project and attended our 6-sessions (9 hours) of professional development training workshops in the academic year of 2019/2020. The training workshops delivered digital citizenship education framework and related concepts and teaching methods to the teachers, including digital citizenship, media literacy, digital commerce, digital footprint, digital etiquette, and cyberbullying. Our team also supported teachers to design their school-based digital citizenship curriculum for trial teaching and discussion of feasible pedagogies after the training workshops. After conducting quantitative data analysis before and after the training workshops, the result found that over 90% of teachers are satisfied with the training workshops. Moreover, there was a significant statistical difference in their teaching of digital citizenship on digital law, digital commerce, and digital security and safety dimensions between pre and posttest. They are more willing to teach these topics after the training. Facing the challenges caused by COVID19 in 2020, however, all Hong Kong schools were forced to close down. Therefore, our class observation has been delayed but we still found that teachers can utilize different online learning activities to implement digital citizenship education, though some teachers also reported that they were not confident to teach certain aspects such as legal dimension. This project suggests a need of equipping teachers’ understanding and teaching of digital citizenship education, and revisiting the relevant curriculum. Copyright © 2020 International Conference on Learning and Teaching.