The purpose of this research is to determine the argument levels formed by students in the seventh-grade social studies course in which argumentation-based teaching is performed. The study was carried out by action research of the qualitative research methods. A total of 33 seventh-grade students including 15 male and 18 female students continuing their education in Sehit Cem Ozgul Secondary School located in the central district of Adiyaman province in the academic year 2013-2014 constituted the study group of the research. Social studies course was carried out based on argumentation in the class including the study group which was assigned to achieve the purpose of the research. The "Argumentation Assessment Scale" which was developed by Erduran, Simon, and Osborne (2004) was used to determine the level of arguments formed by students depending on the problem status. As a result of the analysis of the data obtained, it was concluded that in the seventh-grade social studies course, in which argumentation-based teaching was performed, students produced arguments at Level 2 during the first activity at the most, at Level 3 during the second activity, at Level 5 during the third activity and at Level 4 during the fourth and fifth activities. This finding can be interpreted as that a positive development occurred in students' argument levels through the process and that their argument levels and quality increased. Furthermore, it was also revealed that the argument levels of students showed differences in terms of weekly activities, that students used more rebuttal in the activities to which they felt closer such as career choice and included current issues in their arguments. Based on these results, suggestions were made such as a more frequent inclusion of the activities designed in accordance with the method of argumentation in the social studies curriculum and course books, and teachers' requirement to prepare environments in which they could include students into the argumentation process.