This study aims to improve the students' activeness and learning outcomes of Social Studies through cooperative learning of the game model. This was a classroom action research study employing a spiral design by Kemmis & Taggart. The research subjects were grade VIIIB students of SMPN 1 Bantarsari, Cilacap. The study was conducted in the first semester in academic year of 2013/2014. The researcher was the action implementer whereas the collaborator was the Social Studies teacher, who acted as the observer. The study was conducted in three cycles, each of which consisted of two meetings. The collected data were analyzed by means of the descriptive analysis technique. The results of the study are as follows: the students' activeness in Cycle I attained a score of 61.61 (moderate), in Cycle II it improved to 72.58 (good), and in Cycle III it improved to 80.65 (very good). The class mastery of the students' learning achievement in Social Studies at the end of Cycle I was 48.48 % with a mean score of 63, at the end of Cycle II it improved to 80.65 % with a mean score of 72, and at the end of Cycle III it improved to 96.78 % with a mean score of 81.