Erika Dewi Kurnia Pengarang Arif Widyantoro, M.Pd., B.I Dosen Pembimbing 1 Niken Kencono Ungu, M.Pd Penguji 1 Arif Widyantoro,M.Pd.B.I Penguji 2

English helps us to get information. Vocabulary is one of the elements to master, and this is important. Based on some difficulties in learning English, especially to improve vocabulary. Vocabulary is an important component of the English teaching and learning process (Indrasari, Novita, and Megawati, 2018). Teachers must be able to find creative and effective ways to teach vocabulary to their students. This research purposes to find out the effectiveness of the repetition drill technique with Duolingo application for improving vocabulary at seventh graders of MTs Al-Huda Reban. The method uses in this research is quantitative. The type of the research use experimental design conducted two classes, each class consisting four meetings. One class study English with Repetition drill technique with Duolingo application and one class without this technique. It can be seen from the experimental class show that score is 80,54 while the controlled class score is 74,46. With the result of T-test means that the null hypothesis (H0) is rejected and the alternative hypothesis (H1) is accepted since the significant value (2-tailed) 0,006 is lower than alpha = 0,05. And bsed on the results of the N-Gain calculation the average value in 55.0822 included in the moderate effective category. So, it can be concluded that the use of repetition drill technique with Duolingo application is effective to improve vocabulary.