The purpose of this study is to clarify the use of expressions to maintain cohesion in their speech. The examinees are two trainees (SS, RR) trained in a company in Shizuoka prefecture for one year. Three Oral Proficiency Interviews (OPI) were conducted during their training period, the first-month, seventh-month, and twelfth-month. The interviews recorded each time were used as a date for analysis. The result is as follows: there is no evidence to use expressions to maintain cohesion in RRs first interview. RR has not learned Japanese before coming to Japan. But the second interview shows that RR can use a lot of kinds of conjunctions. SS who has learned Japanese before coming to Japan also uses conjunctions in the interviews. These expressions are useful to maintain cohesion in their speech when the learners have not acquired proficiency to product a long discourse. From these results, it can be said that these two trainees attempted to maintain cohesion in their speech consciously with their limited Japanese oral proficiency.