摘要
民事法律关系中不当得利作为债的发生原因之一，在社会经济交往日益复杂的背景下，其构成要件及返还范围的明确对维护交易秩序、保障当事人合法权益具有重要意义。本文旨在深入剖析不当得利的构成要件并确定其返还范围。通过对国内外相关法律法规、司法解释以及经典案例进行梳理与对比分析，结合法理学理论研究，发现不当得利的构成需具备一方获得利益、他方受有损失、取得利益与所受损失间存在因果关系且无合法根据四个要件。关于返还范围，原则上受益人应将所获全部利益返还受损人，若受损人所受损失超过受益人所得利益，则应在利益范围内返还；当受益人为善意时，仅在现存利益范围内返还，恶意受益人则需承担更多责任。创新之处在于从多维度构建了不当得利构成要件体系，并细化不同类型受益人的返还规则，为司法实践提供更为精准的裁判依据，有助于完善我国民事法律制度建设，促进社会公平正义实现。
关键词：不当得利；构成要件；返还范围
Abstract
Unjust enrichment, as one of the causes of debt in civil legal relationships, plays a crucial role in maintaining transactional order and protecting the legitimate rights and interests of parties, especially against the backdrop of increasingly complex socio-economic interactions. This paper aims to thoroughly examine the constitutive elements of unjust enrichment and determine its scope of restitution. By systematically analyzing relevant domestic and international laws, judicial interpretations, and landmark cases, combined with theoretical research in jurisprudence, it is found that the formation of unjust enrichment requires four essential elements: one party must obtain a benefit, another party must suffer a loss, there must be a causal relationship between the obtained benefit and the suffered loss, and there must be an absence of a legal basis for such benefit. Regarding the scope of restitution, the principle is that the beneficiary should return all acquired benefits to the aggrieved party; if the loss exceeds the benefit received, restitution shall be made within the limits of the benefit. When the beneficiary acts in good faith, restitution is limited to the extent of existing benefits, whereas a malicious beneficiary bears greater responsibility. The innovation of this study lies in constructing a multidimensional system of constitutive elements for unjust enrichment and refining the rules of restitution for different types of beneficiaries, thereby providing more precise criteria for judicial practice. This contributes to the improvement of China's civil legal system and promotes the realization of social equity and justice.
Keywords：Unjust Enrichment; Constituent Elements; Scope Of Restitution
目 录
摘要 I
Abstract II
一、绪论 1
(一) 研究背景与意义 1
(二) 国内外研究现状 1
(三) 研究方法概述 2
二、不当得利的构成要件分析 2
(一) 无法律上原因之认定 2
(二) 利益取得之事实判断 3
(三) 受损方与受益方关系 4
(四) 构成要件间的逻辑关联 4
三、不当得利返还范围界定 5
(一) 返还范围的基本原则 5
(二) 原物返还与价值返还 5
(三) 必要费用与有益费用处理 6
(四) 特殊情形下的返还调整 7
四、不当得利制度适用问题 7
(一) 法律适用中的争议点 7
(二) 与其他民事责任竞合 8
(三) 实践案例中的适用难点 9
(四) 完善不当得利制度建议 9
结 论 11
参考文献 12
民事法律关系中不当得利作为债的发生原因之一，在社会经济交往日益复杂的背景下，其构成要件及返还范围的明确对维护交易秩序、保障当事人合法权益具有重要意义。本文旨在深入剖析不当得利的构成要件并确定其返还范围。通过对国内外相关法律法规、司法解释以及经典案例进行梳理与对比分析，结合法理学理论研究，发现不当得利的构成需具备一方获得利益、他方受有损失、取得利益与所受损失间存在因果关系且无合法根据四个要件。关于返还范围，原则上受益人应将所获全部利益返还受损人，若受损人所受损失超过受益人所得利益，则应在利益范围内返还；当受益人为善意时，仅在现存利益范围内返还，恶意受益人则需承担更多责任。创新之处在于从多维度构建了不当得利构成要件体系，并细化不同类型受益人的返还规则，为司法实践提供更为精准的裁判依据，有助于完善我国民事法律制度建设，促进社会公平正义实现。
关键词：不当得利；构成要件；返还范围
Abstract
Unjust enrichment, as one of the causes of debt in civil legal relationships, plays a crucial role in maintaining transactional order and protecting the legitimate rights and interests of parties, especially against the backdrop of increasingly complex socio-economic interactions. This paper aims to thoroughly examine the constitutive elements of unjust enrichment and determine its scope of restitution. By systematically analyzing relevant domestic and international laws, judicial interpretations, and landmark cases, combined with theoretical research in jurisprudence, it is found that the formation of unjust enrichment requires four essential elements: one party must obtain a benefit, another party must suffer a loss, there must be a causal relationship between the obtained benefit and the suffered loss, and there must be an absence of a legal basis for such benefit. Regarding the scope of restitution, the principle is that the beneficiary should return all acquired benefits to the aggrieved party; if the loss exceeds the benefit received, restitution shall be made within the limits of the benefit. When the beneficiary acts in good faith, restitution is limited to the extent of existing benefits, whereas a malicious beneficiary bears greater responsibility. The innovation of this study lies in constructing a multidimensional system of constitutive elements for unjust enrichment and refining the rules of restitution for different types of beneficiaries, thereby providing more precise criteria for judicial practice. This contributes to the improvement of China's civil legal system and promotes the realization of social equity and justice.
Keywords：Unjust Enrichment; Constituent Elements; Scope Of Restitution
目 录
摘要 I
Abstract II
一、绪论 1
(一) 研究背景与意义 1
(二) 国内外研究现状 1
(三) 研究方法概述 2
二、不当得利的构成要件分析 2
(一) 无法律上原因之认定 2
(二) 利益取得之事实判断 3
(三) 受损方与受益方关系 4
(四) 构成要件间的逻辑关联 4
三、不当得利返还范围界定 5
(一) 返还范围的基本原则 5
(二) 原物返还与价值返还 5
(三) 必要费用与有益费用处理 6
(四) 特殊情形下的返还调整 7
四、不当得利制度适用问题 7
(一) 法律适用中的争议点 7
(二) 与其他民事责任竞合 8
(三) 实践案例中的适用难点 9
(四) 完善不当得利制度建议 9
结 论 11
参考文献 12
