Examining the reasons for the increasing number of Iranians learning German and creating of a first theoretical basis for that is the subject of this paper. In this regard, 370 Iranian learners of German from the German Language Institute in Tehran were questioned and their motivations were studied mainly based on the theory of "L2 Motivational Self System" (L2MSS). Investigating this research related to the psychological concept of "possible selves" and comparing it with the results of research conducted in the learning of English indicates that the motivation for learning German has a significant relationship with the components of the L2MSS, namely, "L2 Ideal Self," "L2 Ought-to Self," and "L2 Learning Experiences." The achievement of this research can be effective in adopting foreign language policies in formal and informal educational areas in Iranian learning context.