Motivation as one of the most important areas in language learning has been extensively investigated based on various models and theories. Recent motivational theories on L2 learning emphasized the importance of the possible 'selves' in motivating learners. This paper analyzes and compares the two constructs of Ought-to L2 self and Ideal L2 self in Iran EFL context, considering Dörnyei's (2009) L2 Motivational Self System as the main theoretical framework. Participants in this study are 216 B.A. senior students majoring in English. A questionnaire comprising seven motivational dimensions was used as the data collection device. Analysis of the results revealed that although both of these constructs are significant and may overlap, Ought-to L2 self construct mainly mediates for explaining Iranian EFL learners' motivation. Therefore, language learning motivation in unique context of Iran is greatly affected by extrinsic factors.