A letter of credit plays very important roles in rational and smooth international trade. But the parties to letter of credit transactions can bring about many troubles and losses in such transactions because of ignorance and limits of their rights and responsibilities. The purpose of this study is to analyze a legal position of confirming bank and limits of responsibilities of the confirming bank on the UCP and authoritative decisions by ICC. I attempts to analyze a legal position of confirming bank and limits of responsibilities between the confirming bank and the contract parties at the documentary credit transactions on the basis of theoretical, lawful, and international transactions.