The purpose of this study was to validate Dornyei``s (2005, 2009) L2 Motivational Self System (Ideal L2 self, Ought-to L2 self, and L2 learning experience) in Korean college contexts as a follow-up study of Kang (2014). This study examined the effects of L2 motivations on motivated behavior of Korean university students through stepwise regression analyses using questionnaires. The results showed that the L2 Motivational Self System explained motivated behavior better than Gardner``s (1985) integrativeness. However, the two components, L2 learning experience, and Ought-to L2 self, played more important roles than ideal L2 self in L2 motivation. In addition, this study revealed some differences between high and low proficiency levels. Even though L2 learning experience strongly and equally explained the motivated behavior of both levels, the low levels were influenced by more affective sides such as integrative orientation and interests in foreign languages, while the high levels were influenced by pragmatic values of L2 learning. However, gender differences in L2 motivations did not appear in Korean contexts. The theoretic discussions will be made at the conclusion.