This book examines a ubiquitous, yet under-researched, area of language education, i.e., language teachers use of curriculum materials. It particularly focuses on EFL teachers use of prescribed curriculum materials in higher education in Mainland China and presents a qualitative, multi-case study involving four Chinese EFL teachersand eight students (two students from each teacher class) at one university in Mainland China. Drawing on data from pre-lesson and post-lesson interviews with the teachers, lesson observations, and documents in three consecutive semesters at the target university, the book delineates the processes of materials useinclassroom settings. It also identifies four domains of factors that influenced the enactment of curriculum materials.  Most importantly, by adopting Vygotsky (1978) mediation theory and Remillard (2005) participatory perspective, the book constructs a curriculum enactment mediation model to reveal the complex and mediated relations among teachers, learners, curriculum materials, and context. It also recommends practical implications for materials developers, teacher educators, administrators, and policymakers.