《九民纪要》第44条、第45条和第71条就以物抵债问题进行了系统性的表述，给近年来民商事案件中频繁出现的以物抵债问题裁判提供了新思路。经过梳理近年来的司法判例和理论学说，关于以物抵债主要存在以下三方面的问题，一是以物抵债合同的涵摄范围界定不清，由于其同时兼容了担保功能和清偿功能，故而对以物抵债法律性质的解释学说纷繁复杂，没有统一定论，因此在司法实务中存在大量类案不同判现象。二是关于以物抵债的合同成立和合同效力存在争议。抵债物的交付是否决定以物抵债合同的生效？清偿期届至前签订的以物抵债合同是否会因违反物权法定、流质流押禁止或者高利禁止的法律条款而归于无效？债权人依清偿期届至前签订的以物抵债协议请求转移抵债物所有权的请求能否得到支持，请求权基础为何？以物抵债合同发生债权效力还是物权效力？三是以物抵债合同的履行和违约救济问题，在双方当事人无约定的情况下，抵债物是否需要清算受偿？关于以物抵债成立后新旧债的履行顺序上，双方当事人是否有选择权？以物抵债合同的履行出现履行瑕疵或履行违约，债权人如何主张违约责任以及主张何种类型的瑕疵担保责任？笔者在《九民纪要》既定的框架下，结合最高院的指导案例，通过实证研究、比较研究和法解释学的方法，对上述问题进行探讨并给出了回应。本文分别讨论了以物抵债合同的定义、性质、类型和构成要件，对于担保型的以物抵债合同，包括让与担保合同和后让与担保合同，重点讨论了担保合同效力、担保物权效力和公示手段；对于清偿型的以物抵债合同重点讨论了其与代物清偿、新债清偿和债之更新等传统民法的联系与区别，对于双方当事人未做约定的以物抵债合同的解释进行了梳理。在此基础上提出了将担保功能从以物抵债合同剔除的设想，并进一步探讨了清偿型以物抵债的抵债物价格风险负担规则、新旧债履行顺序、瑕疵担保责任和违约责任的适用，期冀于构建出完整的以物抵债合同体系。

Article 44, Article 45 and Article 71 of the " Ninth National Court of Civil and Commercial Trial Work Conference "（No.254 [2019] of The Supreme People's Court）systematically express the issue of the contract of paying the debt by a thing, which provides a new idea for the judgment of the contract of paying the debt by a thing which frequently appears in civil and commercial cases in recent years.After combing the judicial precedent and theory in recent years, there are three main problems about the contract of paying the debt by a thing. First, the scope of the contract is not clearly defined, because it is compatible with the guarantee function and the liquidation function at the same time, so the interpretation of the legal nature of the contract is complex, there is no unified conclusion, so there are a lot of different judgments in judicial practice. Second, there are disputes about the establishment and validity of the contract. Does the delivery of the mortgaged property determine the effectiveness of the contract? Will the contracts signed before the end of the liquidation period be invalid due to the violation of numerus clausus of the property law, the prohibition of liquid pledge or the prohibition of high interest? Can the creditor's claim to transfer the ownership of mortgaged property in accordance with the agreement signed before the end of the liquidation period be supported, and what is the basis of the claim? Does the contract of debt for property have the effect of creditor's right or the effect of real right? The third is the performance of the contract and the remedy for breach of contract. In the absence of an agreement between the two parties, does the mortgaged property need to be liquidated? As for the order of performance of the old and new debts after the establishment of the contract of paying the debt by a thing, do both parties have the right to choose? When the performance of the debt for property contract is defective or breach of contract, how can the creditor claim the liability for breach of contract and what kind of guarantee liability for defects?In the framework of “Ninth National Court of Civil and Commercial Trial Work Conference”, the author discusses and responds to the above problems through empirical research, comparative research and legal hermeneutics, combined with the guidance cases of the supreme college. This paper discusses the definition, nature, types and constituent elements of the contract of paying the debt by a thing. For the contract with guarantee function, including the transfer security and the post transfer security, this paper focuses on the effectiveness of the contract, the effectiveness of real right of the guarantee contract and the method of publicity; For the the contract with liquidation function, this paper focuses on the relationship and difference between it and the traditional civil law concepts such as the datio in solutum，new debt liquidation and change of debt. This paper combs the interpretation of the contract of paying the debt by a thing that the two parties have not agreed on. On this basis, this paper puts forward the idea that the guarantee function should be removed from the contract of paying the debt by a thing, and further discusses the rules of price risk bearing, the order of performance of new and old debts, the warranty against defects and the liability for breach of the contract, so as to build a complete system of the contract of paying the debt by a thing.