197 13 Concept-Based Instruction of Chinese as a Second Language Jie Zhang and Xian Zhang Introduction Over the past two to three decades, China’s increasing global influence has generated world- wide interest in Chinese language teaching and learning. As a result, Chinese as a second language (CSL) has been recently recognized as an independent discipline of study (Ke, 2012). Yet as a new discipline, CSL is still in its initial stage of disciplinary building (Wang & Ruan, 2016). Much work needs to be done so that continued growth of CSL can be sup- ported by a well-constructed, coherent disciplinary discourse. Among the many challenges CSL faces, a constant, perplexing question of the field concerns the role of research in CSL instruction. CSL researchers and practitioners have been asking such questions as, what is the role of theory in CSL teaching? How is research relevant to teaching? How can we bridge the gap between theoretical studies and instructional practices? How should we sup- port CSL development through theory-based practices? In this chapter, we focus on concept-based instruction (CBI), an empirical research and teaching approach in the tradition of sociocultural theory (Lantolf & Thorne, 2006). With its tenet to unify theory and practice, CBI offers an original, viable solution to the challenges that the field of CSL is facing. Although CBI was only applied to the context of CSL very recently, with Lai (2012) being the first study in this area, the small number of studies adopt- ing a CBI approach has nevertheless presented powerful evidence regarding the effects of CBI in supporting CSL learners’ development of conceptual understanding and language proficiency (e.g., Ai, 2015; Kao, 2014; Lai, 2012; X. Zhang, 2014). This chapter begins with a brief historical overview of CSL as a field and how CBI fits into the ongoing discourse. Then, we introduce some critical topics discussed in the avail- able literature on CBI in the CSL context. This is followed by a review of current research, findings, and methodology of CBI. We then propose suggestions for pedagogical practice for those who are interested in adopting CBI in their instructional practices. We conclude the chapter by pointing out promising directions to push forward this line of research from aspects of research design, scope of topics, and CBI materials development.