Non-Chinese-speaking (NCS) South Asian students, as ethnic minority group in Hong Kong, are the main disadvantaged social cohort in Chinese language learning. It has been a challenge for L1 Chinese teachers to conduct L2 Chinese teaching to NCS students with diversified native languages and socio-cultural backgrounds. "Reading to Learn, Learning to Write" (R2L) pedagogy has proven effective in L2 English teaching to aboriginal students in Australia and has been focusing on teaching English in other parts of the world [Rose, D., and J. R. Martin, 2012. "Learning to Write, Reading to Learn: Genre, Knowledge and Pedagogy in the Sydney School." London: Equinox]. The current study aims to explore the effectiveness of "R2L" pedagogy to teach Chinese written composition of discussion to NCS students in Hong Kong. Through in-class teaching, data were collected from classroom observation and pre/post-tests in order to understand the performance of NCS students in Chinese written composition before and after the application of R2L pedagogy. Students' learning experience in R2L sessions will also be perceived through interviews. Through integration of reading and writing, the R2L pedagogy provides students with abundant support in language input and output. Moreover, NCS students have shown great improvements in writing after R2L teaching.