While concluding a contract for international sale of goods, the parties thereto may choose American law to be applicable to the contract. The circumstances under which American law may be chosen according to American conflict of law rules are examined by the author. In case of disagreement between the parties regarding the meaning of the provisions of the contract, the construction of the contract may be required to clarify the contract terms. The purpose of the present article is to highlight the particularities of American law, which could face the Russian partner, in case of disagreement between the parties on how the contract is to be construed. The article concerns the issue of applicability under American law of the terms and conditions on which the parties agreed before the conclusion of the contract, and which contradict or amend the existing contract. The author of the article examined the concept of a waiver and in which form it may be done, if a contract for international sale of goods is concluded with Russian partner.