This research was aimed at investigating the effectiveness of using hangaroo game for teaching vocabulary at seventh grade of SMP N 3 Sokaraja in academic year 2014/2015. This research used quasi experimental research. The participants of this research were the students in SMP N 3 Sokaraja. The two classes were chosen as the experimental and control classes. To achieve the goal, pre-test and post-test were used to get data. Pre-test was given to know early competence of the participants in vocabulary. There was post test after the treatment. The result of the research showed that there was a significant difference after the treatment of using hangaroo game. The t-test result was 3.8208 while the t-table with the significant level 0.05 in df 60 was 1.671. The result was higher than t-table (3.8208 > 1.671). It means that hangaroo game was effective for teaching vocabulary at seventh grade of SMP N 3 Sokaraja in academic year 2014/2015.