The research design of the study was classroom action research. In this research, there were four phases, planning, acting, observing and reflecting. This research will be conducted by some cycles. The researcher investigated the eight grade students vocabulary mastery of SMP Negeri 2 Sajingan Besar which was started in June and ended in july 2023. In this vocabulary action research, the students were joined in the classroom there were 12 students failed the test and 8 students passed the test. In the Cycle I the researcher also gives post test, and there were 7 students got less score than criteria of success, and 13 students passed. It means that this cycle were unsuccessful, because the target of the criteria of success were 85%. So the researcher continued in the next cycle. In the cycle II the researcher changed strategy, the strategy was ask the students to practice in front of class. The result of post test in the cycle II there were 2 students who failed and 18 students passed. The students were more interesting with the lesson and they could improve their vocabulary mastery.
Based on the result of the study showed that the students’ vocabulary mastery was increased. To english teacher it is expected to motivate the English teacher to apply a useful teaching technique to improve the students’ vocabulary.
For the other teacher, the researcher suggest them to be useful as a references before making a research dealing with implementation of Blindfold Game Technique in improving students’ vocabulary mastery.

Keywords: Blindfold Game, Improve, and Vocabulary Mastery