The aim of the research carried out by the researchers was to determine the effectiveness of using word wall media to improve students' vocabulary mastery of the 10th Graders of SMK Bina Negara Gubug in Academic Year 2023/2024. The type of this study was a quasi-experimental design and the method was a quantitative method. The population of this study consisted of 28 students of TKJ 2 as the experimental class and 28 students of TKJ 1 as the control class. The tryout test for TKJ 3 was done to know the validity and reliability of the instrument. Pre-test and Post-test were given to the experimental and control class. The result of the pre-test for experimental for experimental class was 66.00 and the control class was 64.50. Meanwhile the result of the post-test for the experimental class was 80.00 and the control class was 78.57. T-test calculation showed that there was a significant difference. The result of the analysis shows that sig (2-tailed) was 0.001<0.05 which means that Ho was rejected and H1 was accepted. As a result, it could be concluded that the use of the word wall media was effective in improving students’ vocabulary mastery.
Keywords: effectiveness, word wall media, vocabulary mastery