This study probes how cultural contents are represented in middle school English textbooks based on the 2015 revised national curriculum. To this end, culture-related sections of 15 textbooks were analyzed in terms of five aspects: cultural subject matters, cultural types, backgrounds, activities for cultural learning, and language integration. The results reveal that the middle school textbooks deal with everyday life of various cultures, including tasks for introducing Korean culture. The three culture types are provided at a relatively balanced ratio, but as the grade goes up, the portion of spiritual culture increases whereas that of material culture decreases. As for cultural background, non-English cultures in the outer and expanding circle are the most frequently presented. In the analysis of cultural learning activities, searching and communication activities connected to speaking and writing have a large portion, but experiential activities are rare. 45.5% of cultural activities are presented in a single communication skill and 54.5% of them are integrated into two or more skills. Finally, based on the study results, some suggestions for effective culture education to attract students' spontaneous participation in middle school English classes are presented.