Background: The CEFR, ever since its inception, has had profound impact on language teaching, learning, and assessment not only in Europe but also in other parts of the world. This study focuses on the adaptability of CEFR writing descriptors in the context of Test for English Majors (TEM). Methods: First, we constructed a questionnaire based on the descriptors collected from various sources in order to elicit university teachers' views on the importance of these descriptors. A revised version was produced based on the feedback from the initial questionnaire survey. In order to further investigate what level or levels these remaining descriptors would fall into, 35 university teachers of English were invited to complete the revised questionnaire while rating 36 TEM writing scripts. Results: Band-setting of the descriptors was initially determined on the basis of the questionnaire data, the result of which was the draft scale of writing ability. In order to collect further evidence for our calibration of the descriptors, eight university teachers of English were interviewed. Based on the interview data, some descriptors were fine-tuned before the scale was finalized. Conclusions: The results have shown that CEFR writing descriptors can be used in the description of the writing ability of TEM candidates, but most of the CEFR descriptors surveyed have had their original level altered in our writing ability scale.