The 3rd International Conference on Science of Cyber Security (SciSec’2020) will be held August 9-11, 2020 in Shanghai, China. The conference is organized by Fudan University. This new forum was initiated in 2018 and aims to catalyze the research collaborations between the relevant communities and disciplines that can work together to deepen our understanding of, and build a firm foundation for, the emerging Science of Cyber Security. Publications in this venue would distinguish themselves from others by taking or thinking from a holistic perspective about cyber security, rather than a building-block perspective.