This paper explores the influences of CEOs’ dual roles (one person serving as both CEO and board chairman) on firms’ technological innovation. Using a sample of China’s listed firms for the period 2003-2014, this study finds that CEO duality promotes the firms’ technological innovation. Specifically, we find that firms with CEO duality invest more in innovation, obtain more patents, and achieve greater innovative success for given research and development expenditures. In addition, we find that the impact of CEO duality on increasing innovation is more pronounced for firms under severe supervisions.