Kajian terhadap permasalahan prinsip itikad baik dan transaksi jujur tersebut dianggap cukup penting sebagai bahan pemikiran bagi pembaharuan hukum. Pembaharuan hukum (law reform) pada abad XXI, khususnya yang menyangkut hukum komersial harus dilakukan melalui studi komparatif, mengingat akibat globalisasi ekonomi, interaksi komersial antara negara cenderung mengarah pada penyatuan sistem dan pranata hukum. Oleh karena itu penggunaan metode perbandingan merupakan keharusan. Isu hukum yang mengemuka adalah : Apa yang dimaksud dengan itikad baik (good faith) sebagai konsep hukum dan bagaimana bentuknya dalam prilaku transaksi sehari-hari? dan bagaimana bentuk norma hukum dan penerapannya? Menurut Prinsip UNIDROIT tanggung jawab hukum telah lahir sejak proses negoisasi. Prinsip-prinsip hukum yang berlaku bagi proses negoisasi adalah : (1) kebebasan negoisasi; (2) tanggung jawab atas negoisasi dengan itikad buruk; dan (3) tanggung jawab atas pembatalan negoisasio dengan itikad buruk. Hal mana secara tegas telah menentukan bahwa jiwa (soul) dari transaski bisnis sejak negoisasi sampai pelaksanaan kontrak harus dilandasi dengan prinsip itikad baik dan transaksi jujur. Setiap negara dituntut harus memiliki sikap persahabatan sebagai dasar prilaku bisnis. Sikap ini kemudian harus dikembangkan menjadi prinsip itikad baik (good Faith) dan transaksi yang jujur (Fair Dealing). Kedua prinsip ini harus menjadi "the soul of business" dalam setiap perhubungan antar bangsa yang melewati batas negara/wilayah sehingga dapat berlangsung secara adil dan jujur. kata kunci: Prinsip Itikad Baik (Good Faith), Transaksi Jujur (Fair Dealing), Contract Perdagangan Internasional. Abstract: Study of the problems of the principle of good faith and honest transaction is considered quite important as food for thought to the renewal of the law. Renewal of the law (law reform) in the XXI century, especially regarding the commercial law should be carried out through a comparative study, considering the result of economic globalization, the commercial interaction between countries is likely to lead to the unification of the system and legal order. Therefore, the use of the method of comparison is a must. Legal issues which arise are: What is a good faith (good faith) as the legal concepts and how to shape the behavior of everyday transactions? and how the shape of the rule of law and its application? According to the UNIDROIT Principles of legal responsibility has been born since the negotiation process. Legal principles applicable to the negotiation process are: (1) freedom of negotiation; (2) the responsibility for negotiating in bad faith; and (3) the responsibility for the calcellation negoisasio bad faith. Where it has expressly determines that the spirit (soul) of business transactions from negotiations to contract implementation must be based on the principles of good faith and honest dealings. Each state is required should have an attitude of friendship as the basis of business behavior. This attitude must then be a principle of good faith dikembangankan (good Faith) and an honest deal (Fair Dealing). Both of these principles must be "the soul of business' in any nexus between nations cross-border/region so as to be fair and honest. Daftar Pustaka Atiyah, P.S., An Introduction to the Law of Contract, Oxford University Press, Oxford, 1996. Brownsword, Roger, et. Seq. Good Fait In Contract, Concept and Context, Dartnounth Publishing Company Limited, england, 1999. Bridge, Michael, Good faith in Commercial Contract, Suffolk, England, 1998. Chirelstein, A. Marvin, Concept and Case Analysis in the Law of Contracts, The Foundation Press, Inc., New York, 1993. Davies, F.R., Contract, Sweet & Maxwell, Kondon, 1970. Fried, M. Lawrence, American Law (An Introduction), W.W. Norton & Company, New York, 1984. Fox,F. william., International Commercial Agreement (A Primer on Drafting, Negotiating and Resolving Disputes), Kluwer, Deventer, 1992. Howells, Geraint., Good Faith in Consumer Contracting, Darthnouth, England, 1999. Huala Adolf, Hukum Ekonomi Internasional Suatu Pengantar, jakarta, Rajawali Pers, 1997. Herman, Gerold., Commercial Treaties, In: R. Bernhardt(ed), Encycplopedi of Public Internasional Law, Instalment 8, 1985. Rivera, F. Juan., The Father of The First Brown race Civil Code., UP.Law Center, Guezon City, 1978. Satrio, J., Hukum Perikatan, Perikan Yang Lahir dari Perjanjian, Buku III, Citra Aditya Bhakti, Bandung, 1997. Skippey, C. Karla, short Course in "International Contract". Terjemahan Hesti Widyaningrum, PPM, Jakarta, 2001. Wighman, John., Good Faith and Pluralism In the Law of Contract, Dartnouth, Englang, 1999.