Blended learning which combines face-to-face and online experiences of students by integrating technology into the curriculum is increasingly prevalent in university education. In a context of long time arguments on the educational value of using social networking websites on teaching and learning, this study was conducted in two higher education institutes in Hong Kong, seeking to examine the advantages and challenges of using Facebook for sharing students' assignments, and the achievement of the course objectives in two courses. Results revealed that course assessment in Facebook could facilitate student interaction and their knowledge construction. Privacy, however, is found to be an issue that needs to be looked into specifically in order to facilitate a safe and comfortable educational learning experience of students.