CISG第四条规定CISG只适用于买卖中的实体规则,即买方和卖方因买卖合同所发生的权利义务。该条同时规定CISG不涉及合同的有效性问题,或其任何条款、任何惯例的效力。这就产生了一个问题,即合同效力最终的确定将依赖于国内法,而不同国家对此有不同规定,这就为CISG的充分应用带来了困难,增加了其不确定性。本文拟对这个问题进行分析,指出其存在的问题及可能的解决办法。 Article IV CISG CISG only applies to the substantive rules of the transaction, that is, the buyer and the seller due to the sale and purchase contract rights and obligations. It also provides that the CISG does not deal with the question of the validity of the contract, or any of its provisions, the validity of any practice. This raises the question that the ultimate determination of the effectiveness of a contract will depend on domestic law and that different countries have different provisions on it, which creates difficulties and increases uncertainty for the full application of the CISG. This article intends to analyze this issue and point out its existing problems and possible solutions.