ENGLISH:
This research was aimed to investigate whether the use of Vocabulary Notebook can improve students’ vocabulary mastery at SMP N 7 Sungaiselan despite some implementation problems such as lack of students motivation, students’ difficulty in understanding word, and difficulty in remembering words.

This research employed an experimental design with two groups, namely the experimental group and the control group, each consisting of 27 students. The experimental group was treated with the use of vocabulary notebooks with materials such as asking and giving opinion, asking and giving information, warning and recount text, while the control group did not receive any special treatment. The results of the research showed that the use of vocabulary notebooks was effective in improving students’ vocabulary mastery. This can be seen from the difference in mean scores between te experimental group and the control group. The mean score of the experimental group was 86,00, while the mean score of the control group was 77,52. The difference in mean scores between two groups indicates that the use of vocabulary notebooks significantly improved students’ vocabulary mastery. In conclusion the vocabulary notebooks significantly improved the students’ vocabulary mastery of the 8th grade students at SMP N 7 Sungaiselan.