Microteaching has been developed as a lesson in teacher-training institutions around the world. In a microteaching class, the students are trained by their lecturer to act as classroom or real teachers. Moreover, teaching practice is important to every student teacher, including student English teachers. This study is concerned with an analysis of the teaching simulation done by some English students in microteaching class at Teacher Training and Education Faculty, Syiah Kuala University, Banda Aceh. The sample of this study was random sampling. The subject of this research were six students from two classes of English microteaching lesson. The writer observed the teaching simulations done by the students in the class twice to find out their performances, comparing their first integrated performances and the second ones to find out the impact of the case study reports to the students’ performances. There are six skills observed by the researcher from the students’ performance: 1) skill in opening the class, 2) explaining the lesson, 3) giving various stimuli, 4) organizing the class, 5) asking questions, and 6) closing the lesson. The skills observed at first and second performance are the same for all students. Each skill has components in it and each component has score to be compared. The score derived from comparison of both performances can be used to see how far the students’ progress in teaching. The instruments used in this study were observation checklist, documentation and interview. The observation checklist was used when observing students’ performances, documentation was used to learn about students’ case study and pedagogical content knowledge and interview was used to get the information about the student’s talk about their performance. Here the writer wanted to know whether the case study reports gave better impact or not. Based on researcher’s observation, all students get low scores at the first performance. Then, having had enough experiences in teaching at the first performance, the students could perform better teaching at the second one. Actually, case study report must be handed over after every single performance. But in fact, the lecturer did not ask students to submit it and another lecturer asked students to submit it at the end of semester. To replace it, the lecturers gave any comments and suggestions to develop the students’ performances in teaching. Actually, without having case study report, the students did not realize their weaknesses from their teaching simulations.