Electronic Payment Systems promote international electronic trade by transferring value quickly and effectively and by imposing a minimum of additional costs or risks on the transacting parties. A payment system can be described in terms of liquidity, finality, transaction risk and systemic risk. The requisites of electronic payment systems are how to make payment electronically in manner that is economic, efficient, reliable, and secure. The payment systems such as Electronic Fund Transfers, TradeCard system and Electronic Letters of Credit issued by SWIFT system enable partly sellers, buyers and service providers to settle payment electronically. However they have significant limitations for international electronic trade transactions. For vitalization of electronic trade transactions, requisites and problems of electronic payment systems are as follows: information security such as authenticity, integrity, non-repudiation, and confidentiality; replacing all paper based documents by electronic data exchange such as electronic business Extensible Markup Language; adapting bolero electronic bills of lading; removing barrier to the linkage with the beneficiary and applicant in electronic issuance and advice of letters of credit through closed SWIFT network; establishing the legal infrastructure of international convention, uniform rules and national law for electronic payment systems; developing reliable electronic payment systems such as electronic letters of credit. As a useful electronic payment method, the electronic letters of credit will not only preserve all the advantages of credits over other methods of international payments, but will also improve the security of the credit system. As a result, the International Chamber of Commerce developed eUCP rules for the electronic presentation of documents. Some problems of new eUCP exist such as format and presentation of electronic records, examination and beneficiary's notice for completeness.Accordingly it will be necessary for international chamber of commerce to provide more detailed guide of the banking operations and developing rules for electronic letters of credit.