The purpose of this study is to establish a foundation for effective classroom discussions using issues by empirically verifying the effect of class climate on middle school students’ expression of opinions. To this end, a survey was conducted on 337 students enrolled in middle schools in Seoul, and multiple regression analysis was performed to examine the relationship between variables. The research yielded the following results: firstly, among the sub-factors of class climate, friction and satisfaction emerged as statistically significant variables. Secondly, personal factors such as academic achievement and knowledge level about issues exhibited a significant positive correlation with learners’ expression of opinion, consistent with prior studies. Encouraging learners’ expression of opinions in classroom discussions is crucial for fostering democracy and revitalizing political participation. The findings of this research can serve as a guide for the smooth operation of discussion classes utilizing issues.