侵占不法原因给付物的行为是否成立侵占罪，在国内外的刑法理论和司法实践中存在肯定说、否定说、区分说、折中说等观点。争论焦点主要集中在四个方面：一是应否区分不法原因给付与不法原因委托？二是不法原因给付时，给付人对给付物所享有的所有权是否还受民事法律的保护？三是如何理解法秩序统一性原理？四是倘若不构成侵占罪，该如何规制行为人的行为和处理不法给付物？本文所持观点为否定说。首先，不应当区分给付和委托。区分说在德日等地未得到确定性的理论支持；依照我国法律规定也无法区分给付和委托；区分说提出的终局性给付标准实际上也不能实现区分目的；结合不法原因给付制度一般预防的规范目的，应当认为不法原因给付制度原本就包含不法原因委托。其次，不法原因给付时给付人对给付物的所有权不受民事法律的保护。根据我国法律规定，不法原因给付时给付物的所有权自始、当然、确定不发生变动，依然属于给付人所有，但是此时给付人仅享有所有权之名，无所有权之实，因为给付人对给付物无返还请求权，给付物应当收归国家、集体或者返还第三人。部分学者提出的“国家享有给付物所有权”的观点不能成立，“保护抽象的所有权”的观点也不能成立；我国侵占罪的保护法益不包括委托关系，无需讨论不法原因给付时非法的委托关系应否受保护的问题。再次，采取否定说是对法秩序统一性原理的坚持。法秩序统一性的真正含义是规范目的的统一性，但当刑法与民法规范目的不同时，即民法上不保护某一利益时，刑法上的违法性就不可以相对判断。不法原因给付时，民法规范否定了对给付人财产法益的保护，在刑法上无论如何不能将受领人的行为认定为侵占罪。最后，否定受领人构成侵占罪不会放纵、偏袒受领人。受领人的行为可能构成相关犯罪的共犯、中止犯、预备犯、未遂犯等；如果不构成犯罪，受领人也可能受到行政法上的制裁；“给付物”也会因“不法”而被没收，而不是由受领人保有。

Whether or not someone encroach the illegal reason payment constitute a crime has different opinions around the world, such views as affirmation, negation, distinction, and compromise. The debate mainly revolves around four aspects: First, whether there is a need to distinguish between payment and entrustment; Second, when the illegal cause is paid, whether the owner's ownership of the material to be paid for is also protected by civil law; The third is how to understand the principle of unity of law and order; Fourth, if it does not constitute the crime of usurpation, how to regulate the behavior of the actor and deal with the illegal payment. The view held in this paper is negative.First, no distinction should be made between payment and entrustment. The distinction is that there is no definitive theoretical support in Germany, Japan and other places; According to the laws of our country, we can not distinguish between payment and entrustment. The final payment standard proposed by the division theory can not actually achieve the purpose of distinction; Based on the normative purpose of the general prevention of the unlawful cause payment system, it should be considered that the unlawful cause payment system already contains the unlawful cause entrustment.Secondly, when the unlawful cause is paid, the paying person's ownership of the given object is not protected by civil law. According to the laws of our country, the ownership of the things paid for when the illegal cause is paid is still owned by the payer from the beginning, of course, and no change is determined. However, at this time, the payer only has the name of ownership and no ownership. Because the payer does not have the right to request the return of the goods to be paid, the goods to be paid shall be returned to the state, to the collective or to the third party. The view that "the state enjoys the ownership of the goods" proposed by some scholars can not be established, and the view of "protecting the ownership of the appearance" can not be established; The protective legal benefit of the crime of usurpation in our country does not include the entrustment relationship, so there is no need to discuss whether the unlawful entrustment relationship should be protected.Thirdly, the negation is to insist on the principle of unity of law and order. The real meaning of the unity of the legal order is the unity of the normative purpose, but when the criminal law and the civil law norms have different purposes, that is, the interests that are not protected in the civil law, the illegality of the criminal law can not be judged relatively. When the illegal cause is paid, the civil law norm denies the protection of the property legal benefits of the payer. Therefore, in any case, the behavior of the recipient can not be recognized as an infringement crime in the criminal law.Finally, denying that the recipient constitutes a crime of occupation will not be indulgent and biased towards the recipient. The behavior of the recipient may constitute an accomplice, a suspension, a preparation, or an attempt of the relevant crime; If it does not constitute a crime, the recipient may also be subject to administrative law sanctions; Even without public law sanctions, the goods will be returned to the person concerned rather than being held by the recipient.