Teachers are expected to keep up to date with challenges and expectations that arise in classroom-based language assessment. This study responds to the call for increased research in the area of language assessment literacy in the context of classroom-based assessment. In particular, our research provides insights into assessment literacy training for in-service teachers of English as a foreign language (EFL). By way of gap analysis based on a questionnaire of 344 EFL teachers in Chinese middle schools, this study found that EFL teachers investigated were nearly at the functional level of CBLAL, and that they expected to be procedurally and conceptually literate through in-service training so as to understand the central concepts of classroom-based language assessment and use their knowledge in practice. The study will shed light on views regarding the assessment literacy topics that are important to be included in in-service EFL teacher training programs.