This paper aims to analyze the role of a branch of a Japanese bank in the internationals financial centers and its change during the Interwar period. Branches of international exchange banks generally buy bills for goods exported from where they exist, to collect bills for goods imported to where they exist, and to transfer funds with other branches. In addition to these "ordinary" businesses branches in the international financial centers raise funds by selling bills there or by borrowing money from other banks, to makes investments for securing reserves, and to advise letters of credit issued by large banks there. This paper sheds light on these activities of the Yokohama Specie Bank, which was the largest international exchange bank in Japan before the Second World War and shows that branches in London and New York facilitated the flow of funds within the bank. The Interwar period saw significant change in international money flow as New York grew to an international financial center, which was as important as London and also saw the Great Depression and international conflicts after that. This paper analyzes how businesses of the two branches changed in order to cope with turbulence in the financial markets.