After calculated the data to be percentage, we found that 30 third year students of RMUTI who are studying in Academic Reading class in this semester think that the most problem of using collocation is low knowledge of grammatical collocations that is 83.33 percent. The following problems are lexical and grammatical, creative invention and analogies, paraphrasing, synonym that are 76.67, 70, 60, and 15 percent respectively