不法原因给付制度是一项民法制度，其意涵为给付人出于不法目的给付财物时，丧失对该财物的返还请求权。现实中大量存在给付方出于不法原因给付财物而受领方实施欺诈行为的情形。本文所讨论的可能与诈骗行为交织的不法原因给付行为指基于主观或客观上违反国家强行法的原因实施的终局和非终局性给付。给付人在实施上述行为之后，就需要承担返还请求权灭失的不利后果。但是民事法律关系中不利后果的分配不等于民事违法性的评价。不法原因给付制度中并不包含对受领人行为的民事认可或授权。因此对受领人的行为进行刑事违法性评价并不会引起法秩序内部的矛盾冲突。本文认为，在诈骗罪的行为模式中，不法原因给付情节只会对受害人受欺诈交付财物和受害人受到损失两个构成要件要素产生影响。财产处分行为中，受害人虽然抱持不法目的，但该不法目的与行为人欺诈行为引发的错误认识之间并不存在冲突。只要行为人的欺骗行为引发了被害人关于财产处分的错误认识，并且被害人基于该错误认识处分了财物，就符合诈骗罪的犯罪构成。受害人即给付人是否具有其他主观或客观的不法原因，不影响犯罪的成立。在被害人损失的评价中，不法原因给付物具有值得刑法保护的法益，应当被评价为财产犯罪中的财物，给付人具有整体财产的损失。首先，主观原因不法的情况下，给付物的权利瑕疵是在给付行为之后出现，此时诈骗犯罪已经既遂，该权利瑕疵不影响犯罪成立；客观原因不法的情况下，给付人虽然不拥有合法的民事权利，但是其对给付物的占有仍然应当经由法定程序改变，同时受领人并不具有可以与给付人的占有相对抗的权利，该占有属于应当受到保护的法益。其次，根据法律—经济的财产说，主观原因不法的情况下，不法原因给付物属于具有民事权利基础的财物，应当作为财产犯罪中的财物被加以保护；客观原因不法的情况下，虽然财物本身具有不法性（如违禁品），但是只要对其加以保护有利于法秩序整体价值的实现，并且无损于法秩序统一性，法秩序就应当对其予以承认。最后，根据整体财产说，给付人在给付行为之后经济利益受到减损，并且没有达到交易目的，应当认为受到财产损失。为了保证不法原因给付制度目的实现，在认定受领人成立诈骗犯罪之后，应当对给付物的权属进行确认，再进行涉案财物处置。

The system of unlawful cause payment is a civil law system that means that when the payer pays property for illegal purposes, they lose the right to request the return of the property. In reality, there are a large number of cases where the paying party pays property for illegal reasons and the receiving party engages in fraudulent behavior.The unlawful cause payment behavior that may be intertwined with fraudulent behavior discussed in this article refers to final and non final payment based on subjective or objective reasons that violate the mandatory law of the state. After implementing the above actions, the payer needs to bear the adverse consequences of the loss of the restitution right. However, the allocation of adverse consequences in civil legal relationships does not equal the evaluation of civil illegality. The payment system for illegal reasons does not include civil recognition or authorization of the recipient‘s behavior. Therefore, evaluating the criminal illegality of the recipient‘s behavior will not cause conflicts within the legal order.This article believes that in the behavior mode of fraud, the circumstances of unlawful cause payment will only have an impact on two constituent elements : the victim‘s fraudulent delivery of property and the victim‘s loss. In the act of property disposal, although the victim holds an illegal purpose, there is no conflict between the victim‘s own illegal purpose and the erroneous understanding caused by the perpetrator‘s fraudulent behavior. As long as the deceptive behavior of the perpetrator triggers the victim‘s erroneous understanding of property disposal, and the victim disposes of property based on this erroneous understanding, it is in line with the criminal constitution of the crime of fraud. Whether the victim or the payer has other subjective or objective illegal reasons does not affect the establishment of the crime. In the evaluation of victim losses, the illegal cause of payment has legal interests that are worthy of criminal law protection, and should be evaluated as property in property crimes. The payer has overall property losses. Firstly, in the case of subjective reasons for illegality, the defect in the right of the thing to be paid occurs after the act of payment, and at this time, the crime of fraud has already been committed, and this defect in the right does not affect the establishment of the crime; In cases where objective reasons are illegal, although the payer does not have legal civil rights, their possession of the goods to be paid should still be changed through legal procedures. At the same time, the recipient does not have rights that can be opposed to the payer‘s possession, and this possession belongs to the legal interest that should be protected. Secondly, according to the property theory of law economy, in cases where subjective reasons are illegal, the property paid for illegal reasons belongs to property with a civil right foundation and should be protected as property in property crimes; In the case of objective reasons for illegality, although the property itself has illegality (such as contraband), as long as its protection is conducive to the realization of the overall value of the legal order and does not harm the unity of the legal order, the legal order should recognize it. Finally, according to the overall property theory, if the economic interests of the payer are impaired after the payment behavior and the transaction purpose is not achieved, it should be considered as having suffered property losses. In order to ensure the realization of the purpose of the payment system for illegal reasons, after determining that the recipient has committed a fraud crime, the ownership of the goods to be paid should be confirmed, and then the property involved in the criminal case should be disposed of.Keywords: Unlawful cause payment;Crime of fraud;Unity of legal order;Legal Interests of Property;Disposal procedure of criminal property.