Teachers' professional learning on social media has received growing attention recently, but research into teachers' academic engagement on social media remains limited. This study aimed to examine what factors motivated university English teachers to engage with academic reading on social media. The determinants of academic reading on social media were identified by semi-structured interviews, which were further validated by quantitative investigation. The results showed that participants' perception of values of content knowledge, pedagogical content knowledge, and students' participation in the classroom affected their intentions toward commitment to academic reading on social media. Additionally, the results revealed that perceived value of pedagogical content knowledge mediated the relationship between perceived value of content knowledge and participants' intentions toward academic reading on social media while also mediating the relationship between perceived value of students' participation in the classroom and the participants' intentions toward academic reading on social media. These findings yield implications for the professional development of university teachers and the development of pedagogical content knowledge.
Keywords: Chinese university English teachers; academic reading; content knowledge; pedagogical content knowledge; professional development; social media.