The present study aimed to investigate the contribution of oral language skills, linguistic skills, and transcription skills to Chinese written composition among Grade 4 students in Hong Kong. Measures assessing verbal working memory, oral language skills, linguistic skills (i.e., syntactic skills and discourse skills), transcription skills (i.e., spelling), and written composition were administered to Chinese fourth graders ("N" = 259). Hierarchical multiple regression results showed that only spelling and syntactic skills contributed significant unique variance to written composition. The relevance of the differences between the spoken Cantonese dialect and Modern Standard Written Chinese to these findings concerning the development of children's written composition is explored.