This paper deals with the interaction pattern between teacher and students in the real classroom lessons. This study was primarily conducted to determine the patterns of classroom interaction produced by the teachers and learners during the class sessions in the bilingual middle-school classrooms in Medan City, Indonesia. The data were spoken texts of teachers from five videorecorded classes (Mathematics, Physics, Biology, English and IT/TIK) during the period of even semester, and were then analyzed by applying the "Flanders Interaction Analysis Categories System (FIACS)" 'Interaction Model' following the frame works proposed by Flanders (1970). From the data analysis, it was found that the talk was dominated by teachers, particularly on the categories of no. 4, 5, and 6, while students practiced no. 8 mostly, and it also indicated that instructor expressions were very overwhelming in each example of assignments amid the class sessions, while understudies reactions or different properties were moderately low in rates in an educator centered classroom aside from in the scene no. 5 (IT Lesson) where understudies took the greater part of the cooperation among peers. The examination likewise demonstrates that elicitation, reaction, and input were deliberately utilized by instructor, and understudies were a piece of the structure of classroom talk exercises. The example, notwithstanding, could be changed relying upon the educator expectation or the times of lesson that understudies learn.