Despite the increasing popularity of English Medium Instruction (EMI) for academic subject teaching in China, there is little research regarding the competencies that an EMI teacher needs for effective EMI course delivery and professional development (PD) in the higher education (HE) context. No research has investigated how those can be recognised through certain kinds of certification. This study fills the gap by investigating teachers' perspectives on competencies, certification and PD of EMI in relation to China through 133 survey returns and 12 semi-structured interviews. Our findings show that teachers have a generally positive attitude on EMI certification and PD programmes though few universities have made either a priority. Competencies required for effective EMI teaching include not only English proficiency and teaching skills through L2 but also skills of instruction in respective academic disciplines. This poses challenges for the design and implementation of EMI PD leading to teacher certification. The lack of official government involvement (at policy level) and institutional involvement (evaluation and faculty promotion) further complicates this issue in a country like China with a top-heavy bureaucracy.