In this introductory chapter, the context of the study is initially examined from two critical dimensions: English language education in Chinese primary schools and English language assessment in China. This section serves to help readers understand the rationale of the study from a contextual standpoint. The following section is dedicated to the theoretical background of the book, which underscores the paradigm shift from large-scale standardized testing to CBA within the field of educational assessment. It provides an overview of current research on CBA, with particular emphasis on its application in L2 contexts. Significant research gaps are also identified, based on which the research purposes and the significance of the research are discussed. Finally, the outline of the book is presented.