This book is one of the representative works of Huang Youchang, a renowned Chinese jurist. It was first published by Jinghua Printing House in 1915, with the second edition released in 1918 and the third edition in 1930. The current version is based on the third edition. The monograph provides an in-depth exploration of the historical origins and fundamental principles of Roman law, as well as its foundational role in modern civil law, commercial law, procedural law, and other legal domains. It also analyzes how modern legal systems have inherited and developed Roman legal traditions, highlighting the enduring research significance of Roman law in the field of modern private law. Structurally, the book consists of  introductory chapters and core chapters. The introductory chapters, drawing upon Sun Yat-sen's "Three Principles of the People" (Sanmin Zhuyi), expound on the manifestations of nationalism, democracy, and livelihood in Roman law, along with the historical periods of Roman law's transmission and development, and major schools of Roman law studies. The core chapters systematically address three principal legal domains: the Law of Persons (Jus Personarum), the Law of Things (Jus Rerum, encompassing property rights, succession, and obligations), and the Law of Actions (Jus Actionum).This seminal work examines Roman law through the lens of modern legal systems, employing modern legal terminology and conceptual frameworks while incorporating substantial modern political and juridical knowledge. It systematically elucidates the nexus between Roman law and modern jurisprudence, unveils the evolutionary trajectory of Roman law in modern contexts, and ultimately achieves a systemic integration of Roman law with modern legal frameworks. Recognized as a seminal work in Chinese legal academia, this book remains an indispensable reference for Roman law studies.