In the laws of many countries around the world, parties are allowed to make a sale contracts while they leave the price undetermined at the time of conclusion of the contracts. Open price term in sale contracts formed in world’s trade. Base on the new market and business environment in the modern world, the importance of up-to-date rules on the open price term has become clearer. In this book, the negative and positive points in open price rules under The United Nations Convention on Contracts for the International Sale of Good, Uniform Commercial Code of the United States and the Sale of Goods Act 1979 of the United Kingdom are analysed in view of putting forward an alternative regulation for open price term. In doing so, a brief historical review on each codification is performed followed by an analysis of the open price regulation. Such information and data have enable the authors of this book to carefully propose a comprehensive article to regulate open price term. Countries whose domestic laws have refused to recognize the open price term in sale contract as well as countries with flaws in their open price legal provision may benefit from the proposed article for open price term in this book. Such endeavor aimed enabling reform will lead to industrial and commercial progress of the people and nation.