Abstract
These past few years, programs of local English as a foreign language (EFL) textbook development were launched to adapt to the newly issued English Curriculum Standards in China. They not only develop Student's Books but also write Teacher's Books as an integral part of their work. How to write a Teacher's Book that exactly meets the non-native speaker (NNS) language teachers' needs was a long-time concern, but few studies have been conducted to address the concern empirically. The present research with a single case design closely examined how a local Teacher's Book writer's understanding of the local EFL teachers shaped the role of the Teacher's Book by looking into the process of an English language teaching (ELT) materials development program in China. It sought to find answers to what the Teacher's Book writer knew about the local EFL teachers, and how this understanding influenced his conceptualization of Teacher's Book development. The findings show that the writer's understanding of local teachers' conventional teaching practice, and their content knowledge (CK) and pedagogical content knowledge (PCK) play a decisive role in shaping the Teacher's Book into materials that provide educational affordances to overcome the local EFL teachers' weaknesses and inject innovation into their conventional practice. These findings have implications for both the international and local ELT materials development programs to compile Teacher's Book for better local use.