In this study, we researched and reviewed how Japanese learners' language level is difference about comprehension of sentences. Specifically, we aimed at answering the following: (1) Enforced to Japanese learner's oral reading task, we reviewed how difference between language level from sentences pause's site and unit. (2) We reviewed if there is possible way that they can be equals or not between acquire process of sentences understanding as a second language or native language. As a result, question of (1), if leaner having a lower level, they put pause frequently and which is sentence's unit is short, for example, they can only understand 'word' and 'phrase'. Then Japanese leaner are easily put pause inapposite place but as a level goes up, the problem is getting lower. Also, as lower level learner, they completed a read aloud task but they didn't understand the sentences. Question of (2), as a lower level leaner, they put pause almost same as Japanese children. However, we also found several different about understanding of sentences.