This paper aims to investigate the effectiveness of Halliday’s Sydney School genre-based approach in teaching Chinese written composition to South Asian ethnic minority students in Hong Kong. Chinese language, with its heightened status in Hong Kong, holds a key for South Asians with low socio-economic status to obtain upward mobility (Shum, Gao, Tsung, and Ki, 2011). However, South Asian ethnic minority students, as a disadvantaged group of second language learners, lack sufficient parental and institutional support in Chinese language learning. The genre-based pedagogy derived from Halliday’s Systemic Functional Linguistics (SFL) was applied in this study to improve Chinese language performance of South Asian ethnic minority students for a better chance to participate in mainstream society. The SFL approach is primarily concerned with language choice in social situations and has been widely applied in sociolinguistics (Hyland, 2007, 2012). Its latest model in language teaching methodology, the ’Reading to Learn, Learning to Write’ (R2L) pedagogy, is a genre-based teaching strategy which is designed to guide students to experience different levels of language through extensive classroom reading and writing activities with selected texts. The current study is intended to extend the approach to teaching and learning Chinese as a second language. The employment of genre-based pedagogy aims to support South Asian students with their learning of Chinese written composition in the senior secondary curriculum. The Chinese teachers involved were first provided with appropriate training in the genre-based approach to language teaching focusing on the genres of Narration and Explanation. Research data were collected while the teachers began to use the genre-based teaching approach, by means of pre-and post-tests after and before genre instruction. Text analysis based on SFL was then employed to analyze the students’ written composition in both pre-and post-tests in order to understand