When two or more people risk accepting contractual obligations, the first reasonable expectation that arises for them in accepting this risk is the adherence of the other party in establishing their line of behavior based on good faith. As the process of creating a contractual legal relationship continues from the time of initial negotiations to the discharge of the obligee, it is obligatory for the legislator and its executives to prevent the entry of bad faith of individuals in each of these contractual stages as much as possible. And in case of malicious interference by any of the contracting parties, based on the legal infrastructure provided in advance, by identifying the legal responsibility of the guilty person, compensate the losses caused to the victim. Of course, the great challenge that exists regarding some complex legal concepts, including contractual goodwill, is the lack of agreement among scholars in obtaining a comprehensive meaning and a single obstacle to them, a problem that has always made legislators hesitate in applying these legal concepts. Therefore, considering that the United States Unified Commercial Code (UCC), is the leader in the wide use of this legal concept and its impact on breach of contract, The present article, based on an analytical study and relying on a critical view of this law in its approach to the nature of contractual goodwill and its role in breach of contracts,