Conceptual Metaphor (CM; e.g., Lakoff & Johnson, 1980, 1999; Kovecses, 2020) is central to our thinking and ubiquitously manifested in our language. Given its importance, the teaching of conceptual metaphors has gained much attention in Cognitive Linguistics and Applied Linguistics. While most empirical studies have focused on specific aspects and domains of metaphorical language, for example, vocabulary (e.g., Boers, 2000), phrasal verbs (e.g., Lee, 2012; Yasuda, 2010), idioms (e.g., Chen & Lai, 2013; Wang, Boers, & Warren, 2019), metaphors with specific source or target domains (e.g., Lai, 2012; Liu & Hsieh, 2020; Wang & He, 2021), little attention has been paid to fostering second language (L2) learners' systematic understanding of CM and holistic abilities in metaphorical meaning-making. This dissertation presents the research that implements Conceptual Metaphor Theory-informed Concept-based Language Instruction (C-BLI; Gal'Perin, 1992; Lantolf & Poehner, 2014; Negueruela, 2003) to systematically teach the Concept of CM and promote learners' development in comprehending, interpreting, producing, and reasoning L2 metaphorical meaning. Micro-genetic analyses (Vygotsky, 1978) tracing eight international doctoral students' conceptual development in five-lesson intervention and comparisons of their performances in the pre-, post-, and delayed post-assessments revealed their transformed metaphorical meaning-making processes through appropriating and internalizing the Concept of CM as a psychological tool (e.g., Kozulin, 1998; Vygotsky, 1903, 1987) over a forty-week period. Through the pedagogical intervention, the learners developed abilities to construct coherent systems of metaphor-related knowledge and used the concept flexibly to make metaphorical meaning across genres of texts and communicative tasks. This dissertation contributes to the growing body of research integrating Cognitive Linguistic and Sociocultural Theory for L2 pedagogy. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]