Student-based instruction is a form of collaborative education that students play an active role in learning the process. Student’s activity is in group forms. The teacher is presenting in class just to answer students’ questions. The paradigm and pattern shifting away from teaching to an emphasis on learning have persuaded power to be changed and moved from the teacher to the student. Being a qualitative research paper, it is an attempt to investigate the impact of student-based instruction on improving IBT scores of Iranian students. The participants of this study will include two groups of male and female students each consisting of 15, all of whom are enrolling in TOEFL classes in Kish English Institute in Tehran. The participants will be assigned to control (N=15) and experimental (N=15) groups. The participants in the experimental and control groups exposed to the same content, but a different instructional method. The participants are 30 students in Advance level in one class, male and female, aged 25-35 years old. SPSS and Independent T-test are used to measure hypothesis of research and to analyze data, respectively. According to the results of this investigation, student-based instruction significantly affects IBT TOEFL scores of students.