Although the purpose of International Convention on the International sale of goods is not to unify the law of state parties, according to Article 9 of the Iranian Civil Code, “the Provisions of the treaties which has been concluded between the Iranian state and other states according to the Constitution are as valid as the Statute”. On the other hand according to the Article 4 of the Constitution all of the codes must be compare in conformity with Islamic law. The International Convention on the International Sale of Goods (Vienna, 1980), seeks to consolidate and harmonize laws governing international sale which Iran's accession to it could lead to the promotion of Iran's foreign trade and economic prosperity. Iran's accession to the said Convention is faced with internal and international restrictions. Some of internal restrictions comprise constitutional restrictions and the absence of comprehensive plans and general policies, as well as the violation of some of the provisions of the Convention by domestic law, and some of international restrictions include the opposition of the world’s Superpowers through economic sanctions as well as the weakness of Iran's economic diplomacy. None of these issues poses a serious challenge to Iran's accession to the convention and what has been done in spite of the extensive efforts of Iranian lawyers in recent years to approximate the provisions of the Convention with domestic law, is the lack of determination among the practitioners.