This paper aims at examining the development of strategy for banking internationalization focusing on small and medium sized banks in Korea. This is the detailed case study dealing with the process of Macquarie banking group(MBG)'s internationalization. The first part shows the background and the purpose of this paper. The second part examines the theories and existing studies in related with banking internationalization. The third part of this paper analyses strategic lessons from the overseas expansion of MBG. The fourth part includes the process of making strategy for internationalization of small and medium banks with the case of how MBG penetrated into Korea in 2000s. Finally, there are three conclusions to take into consideration when small and medium banks seeking internationalization.