This study showed that children’s second language (L2) vocabulary and syntactic awareness were important predictors of the growth of reading comprehension in children who were L2 learners. This implies that teachers should emphasize vocabulary and awareness of syntactic structure in the instruction for L2 learners. Results also showed that students with poor vocabulary and syntactic awareness may cause reading comprehension difficulty. Moreover, teachers are suggested to involve vocabulary and syntactic awareness teaching in contexts of reading as previous findings indicated that teaching the use of context to infer the meaning of unknown words is worthwhile in the language classroom. We also suggested that teachers allow more time for children to practice reading so as to strengthen their reading comprehension and improve general language abilities.