The research was aimed to find out how hangman game can improve the students’ vocabulary mastery, especially in determining the proper meaning of the word, spelling and word used. This research was conducted through classroom
action research (CAR) design. Then, the subject of research was the students of class VII B of SMP Negeri 1 Boyan Tanjung consisting of twenty eight students with detail of 14 male students and 14 female students.This research used
observation and measurement as the technique of data collection. The tools of data collection were field notes and vocabulary tests. Then, the data analysis used in this research was qualitative data analysis to analyze Kualitative data and quantitative data to analyze the quantitative data.The result of this research showed that Hangman Game could improve students’ vocabulary mastery. It
could increase students achievement in vocabulary mastery, and the students’ progress in attitude toward English lessons especially in vocabulary. The students are actively involved in the teaching and learning process. It proved that Hangman Game improves students’ vocabulary mastery in two cycles. The student's score in the first cycle was 64,46 and in the second cycle is 87,14. Based on the research
findings, it can be concluded that Hangman Game media can improve the students’ vocabulary mastery. Moreover, the researcher suggested for the English teacher use Hangman Game media in the teaching and learning process, especially
in vocabulary mastery.

Keyword : Hangman Game, Classromm Action Research, Vocabulary Mastery