Digital media literacy education has become shared responsibility of all educators, school-based initiatives are considered to be a crucial component of digital media literacy education. This 10-week intervention study explores the effects of digital media literacy (DML) course on students' digital media literacy. The participants were 58 fifth graders (M = 11.5 years) from two classes in Beijing. An analysis of covariance (ANCOVA) and structural equation modeling (SEM) were performed to examine the effects of the DML course on the digital media literacy of primary school students. The results provided evidence that the DML course positively impacts students' citizenship participation, but has no significant influence on students' technical skills, critical understanding, or creation and communication. The findings also explained a positive relationship between teacher's scaffolding support and students' digital media literacy.