With the release of the China’s Standards of English Language Ability (hereafter CSE), there is an increasing demand for the study of the application of the CSE for classroom teaching and learning. The purpose of this paper is to investigate the application of the CSE for self- and teacher assessments in EFL writing course. A brief introduction of the course will be provided, then, how teachers and students use the CSE-based scale in self- and teacher assessments will be reported, followed by the description and discussion of the similarities and differences between students and teachers in using the CSE-based scale for assessment. It is hoped that this study will shed some light on the application of CES for classroom-based assessments.