Vocabulary is the main foundation of one's English language skills. English itself consists of four skills, namely listening, speaking, reading and writing. To be able to master these four skills, vocabulary is one of the main components that must be mastered first. Because vocabulary is a vocabulary or a group of words in a language that must be mastered by someone.
The purpose of this study was to determine how the used of visual dictionary media can improve students' mastery of English vocabulary at SMPN 3 Banyuke Hulu. This research was conducted using a classroom action research method consisting of 2 cycles. The research lasted one month with a duration of four meetings where each cycle lasted for two meetings.
The findings of this study are that the used of visual dictionary media in teaching student vocabulary can improve students' vocabulary mastery ability, this can be seen from the acquisition of average scores and classroom situations that clearly show the improvement that occurs. In the first cycle the average value obtained was 59.3 compared to the improvement that occurred in the second cycle the average value obtained was 79.8. The improvement of the classroom situation was be seen from the behavior of students who are more active during the learning process. The results obtained by the researcher prove that visual dictionaries was improve students' vocabulary mastery at SMPN 3 Banyuke Hulu.

Keyword : Visual Dictionary, Vocabulary Mastery,