ABSTRACT Misnawati. 2013. Improving students’ Ability in Mastering Relative Clauses through the Implementation of Gerlach and Ely Model. (A Classroom Action Research at the Third Semester of English Department of Almuslim University, Matangglumpangdua, Bireuen). Thesis. Graduated Program in English Language Education. State University of Syiah Kuala. Advisors: (I) Dr. Sofyan A. Gani, M.A., (II) Abdul Manan, M.Sc., M.A. Ph.D. Keywords: Gerlach and Ely Model, Relative Clauses Starting from the problems faced by the third semester students of English Department of Almuslim University, Matangglumpangdua, Bireuen in Grammar, especially Relative Clauses, the researcher was motivated to do the classroom action research on it. Based on the results of the researcher’s preliminary study that the causes of the students’ problems in using relative clauses are: (1) the lecturer did not has a good instruction in teaching relative clauses. (2) Materials used were not effectiveis possible caused by there is no demand from technique or strategy, so the lecturer only giving items pursuant to book are there her inteaching relative clauses. (3) the lecturer used monotonous techniques, (4) students had difficulties in using conjunctions in relative clauses, (5) students were not able to use relative clauses, (6) students had low motivation in learning relative clauses. So that, the teaching and learning of English grammar was uninteresting for the students and they had difficulties in making sentences. Supported by some theories, experiences, and previous research in grammar, the researcher decides to use Gerlach and Ely model to solve the students’ problem in grammar. The researcher also found new problems when the researcher taught them in cycle I. The problems were (1) the students do not understand how to use defining and non-defining relative clauses. (2) they had difficulties when they translated or gave the meaning of relative clauses into Indonesian. For the purpose, the researcher formulated the research problems, they are: (1) How does Gerlach and Ely model improve the students’ achievement in learning relative clauses? (2) How is the implementation of Gerlach and Ely model in teaching relative clauses? (3) How do the students respond toward the application of the Gerlach and Ely model in learning relative clauses?The objectives of the research was develop Gerlach and Ely model to upgrade the teacher in teaching English and improve to the students’ ability in grammar, especially relative clauses.The research belongs to a classroom action research design in which the researcher and observer work together in designing the lesson plan, implementing the action and making reflection. The subjects of the research are all the third semester students in Unit B at English Department of Almuslim University, Matangglumpangdua, Bireuen. The study was conducted in two cycles by following the procedure of the action research, i.e. planning, implementing, observing, and reflecting. To collect the data, the researcher used some instruments, such as: test, observation checklist, field note, and questionnaire. The obtained data are presented and analyzed in qualitative data procedures. Qualitative data were presented in words, explaining the process of implementing the model.The findings of the research show that the implementation of Gerlach and Ely model through “the super bingo” strategy in grammar class was effective to improve the students’ ability in grammar, especially relative clauses. The improvement of the students’ activities in the classroom can be seen from each cycle. The researcher got the mean score of students’ test in cycle I was 63. 19, and test in cycle II was 78. 82. The result of the students’ responses also indicates had good responses to the implementation ofGerlach and Ely model. Based on the questionnaire given, it was found that mean score for the students’ perception is 4. 22. This means that students responded positively toward the implementation of. Gerlach and Ely model through “the super bingo” strategy. Therefore, the researcher concluded that Gerlach and Ely model through“the super bingo’ strategy could improve students’ ability in grammar, and the students had positive respones toward Gerlach and Ely model through“the super bingo” strategy during teaching and learning process in the classroom, and also this model brings the new situations for the students to be active in learning grammar in the classroom.