The objective of this study is to find out whether students' vocabulary improved if it will be taught by using Flyswatter game.To solve the problem, the writer conduct classroom action research, by implementing flyswatter game. The writer applied one cycle in this research. Each cycle consist of fourth meetings. The participant of this study was one class consists of 24 students. The instrument for collecting the data the writer used observation sheet, test sheet and documentation. Based on the research result, showed the progressive mean of the students. The first meeting was 53.5, second meeting was 55.3, third meeting was 61.9, the fourth meeting was 66.1 the fifth meeting was 75.5. So, the mean in the post test was higher than the pre test. The data from observation sheet indicated that the students got improvement. It indicated that the application of flyswatter game improve students' vocabulary. In conclusion, flyswatter game could improve students' vocabulary mastery at SMPN 2 Tambangan