《中华人民共和国民法典》(以下简称“《民法典》”)第552条所确立的债务加入制度,作为新增设的一项法律设计,其在司法实践中的应用与发展日益受到关注。本文以该条规定为核心,针对债务加入制度的基础理论,并通过相关法律条文的分析,探讨我国立法实践中该制度的具体内涵,明确区分免责式的债务承担与并存式的债务承担的不同特征。文章进一步从债权人、原债务人和债务加入人的不同视角出发,系统阐述债务加入制度对各方主体产生的法律效果。此外,结合最高人民法院关于适用《中华人民共和国民法典》有关担保制度的解释(以下简称“《担保制度解释》”)第36条的规定,比较债务加入制度与保证制度,论述存疑推定规则的合理性,以期厘清我国《民法典》的债务加入制度。Article 552 of the Civil Code of the People’s Republic of China (hereinafter referred to as the “Civil Code”) institutes the legal framework for debt accession, a newly established legal mechanism that has garnered increasing attention in its application and development within judicial practice. This paper focuses on this provision, examining the foundational theory of the debt accession system. Through an analysis of pertinent legal provisions, it explores the specific connotations of this institution within China’s legislative practices, clearly delineating the distinct characteristics of exemptive debt assumption and concurrent debt assumption. Furthermore, the paper systematically elucidates the legal consequences of the debt accession system from the perspectives of creditors, original debtors, and debt accessors. Additionally, by incorporating Article 36 of the Supreme People’s Court’s Judicial Interpretation on the Application of the Guarantee System under the Civil Code of the People’s Republic of China (hereinafter referred to as the “Judicial Interpretation on the Guarantee System”), it compares the d
