One of the sources of interpretation of the Convention on contracts for the International Sale Goods is the principle of good faith. The emergence of the concept of good faith versus Good Faith derives from the contract law of Rome. There is no definition of this principle in the law of the Roman-German or Commonwealth countries, nor in the Convention in question. Lawyers in different countries have generally been reluctant to define it for reasons such as its obviousness or even its difficulty. So that some authors in their article have called the definition of Good Faith "a definition of the indefinable". Others, however, have provided definitions. Given that the Convention on contracts for the International Sale Goods in paragraph 1 of Article 7 declares the principle of good faith as merely a means of interpreting the provisions of the Convention, this article specifically seeks to answer the question of whether good faith as a Is an independent obligation applied to the parties to the contract in the implementation of the obligations or not? The present study, which is based on a descriptive-analytical method and based on a library study written in order to respond to this important issue, examines rules and principles such as the principle of necessity, the rule of abuse of rights and the Estoppel rule to discover the basis of this principle. The provisions of the Convention on contracts for the International Sale Goods seek to identify and identify materials that have been developed in accordance with the principle of good faith in the performance of contractual obligations. as a result; It can be said that the principle of good faith is considered not only as a source of interpretation, but also as a contractual obligation in the implementation of the obligations of the parties.