The subject of this research paper focuses on the documentary letter of credit in accordance with the Omani Law as a banking transaction that played, and still playing, important commercial and economical role on international commercial relationships. I dealt with the documentary letter of credit relying on the Omani and Egyptian Laws and the unified principles and pratices of publication no. 500 and 600. This research explains the meaning, types, contract and parties of documentary letter of credit. Its also shows the relation rising from the documentary letter of credit and the impacts on its contract. The research found a number of results most importantly are: - The documentary letter of credit consists of three parties: ordering client, beneficiary and bank. - The documentary letter of cedit is considered an independent contract from sale contract for which the letter of credit is opened. The research is concluded with recommendations most importantly are: - Urging the Omani legislator to regulate documentary letter of credit in a manner more comprehensive that at the present time as the research touched documentary letter of credit in a numerated items.