This research focus on teaching vocabulary by using Hangman Game. The purpose of this research was known the students’ difficulties to learn vocabularies and the effectiveness of Hangman Game to improve students’ vocabularies at eight grade students of SMPN 2 Bangsri in academic year 2018/2019. The research method is True Experimental group with simple random sampling technique. The sample was class VIII A as Experimental research and class VIII F as a control group. The data is collected through written test item in form of multiple choices with twenty numbers and have analyzed by using t-test formula. The objective of this study is to find out whether there is any significant difference between the students who taught by using Hangman Game and students who are taught without using Hangman Game. The researcher used pre-test and post-test to measure the students’ achievement. The researcher used quantitative measurement to find the result. The analysis of the data showed that there was a significant difference of the students’ achievement between experimental and control class. The average of the students’ pre-test is 71,93 in experimental class and 77,90 in control class. After getting treatment using Hangman Game , the average score of post-test in experimental was higher than control class, 87,42 for experimental class and 80,16 for control class. To measure the significant achievement of the students, the writer used t-test formula also. the result of post test in experimental and control group showed that the t-value was 2,567 while the t-table of 0,05 as the significance level was 2,000 with 60 the degree of freedom (df). It could be described that the t-value (2,567) > t-table (2,000). Based on the result above, it could be concluded that Hangman Game was effective in improving the students’ vocabulary mastery at the eighth grade students of SMPN 2 Bangsr