Nicodemus Dos Reis Pengarang Alexander Home Kabelen Dosen Pembimbing 1 Merlyn K. Nelloe Dosen Pembimbing 2 Alexander Home Kabelen Penguji 1 Santri Emilin Pingsaboi Djahimo Ketua Penguji Merlyn K. Nelloe Penguji 2

This study aims at determining whether the discovery learning method can improve the mastery of English of grade VIII students at SMP Negeri Silawan, Belu Regency. This study used qualitative and quantitative method with a pretestposttest control group design. The research sample consisted of two classes, namely the experimental class that used the discovery learning method and the control class that used the conventional learning method.Data were collected through English mastery tests before and after treatment. Questionnaires were also used to determine students' perceptions of the learning methods used. The data were analyzed using ttest to compare the mean scores of pretest and posttest between the two classes, as well as independent t-test to compare the difference in English mastery between the two classes.The results showed that there was a significant increase in the English language mastery of VIII grade students who used the discovery learning method compared to students who used the conventional learning method. In addition, students in the experimental class also had more positive perceptions of the learning method used.