The letter of bank guarantee of important banking operations in the trade on the domestic and international level, as this process is the establishment of a bank at the request of the client to undertake an independent undertaking to pay the value of the collateral to the beneficiary, and the increasing importance of this banking operation is the largest in the field of international trade, it has a great role in the provision of trust between the parties to the contractual relationship factor, as long as we in the framework of the international nature of the relationship, the problem of the on the applicable law are raised on this banking operation, so there are international rules to try to find a solution to this problem, which is all of the rules of the International Chamber of Commerce in Paris for a year 1992, and the rules of UNCITRAL in 1995, since the conventions a big role in the organization of a speech the bank guarantee in order to establish uniform rules applicable to this contract, also have a role in a statement applicable by law for these two, as was the codification of these rules in written form as bases complementary to the will of the Parties.