The fifth lecture of the Innovation Forum of CASS Law Institute and CASS Institute of International Law was successfully held at the conference room of the two institutes on October 29, 2019. The lecture, entitled “Extraterritoriality: from Concept” was given by Professor Gao Hancheng, Deputy Head of Department of Legal History, CASS Law Institute and Chief Researcher of the innovation project “Inheriting and Drawing on the Essence of Chinese Legal Culture”. It was presided over by Professor Zhang Sheng, a research fellow and the head of Department of Legal History, CASS Law Institute. Mr. Yang Zaiping, Research Fellow and Deputy Head of Department of Theoretical Research, the Party School of Shanxi Provincial Party Committee, Mr. Hu Yongheng, Associate Senior Editor, Editorial Board of Modern Chinese History Studies, Professor Wang Shuaiyi, Associate Research Fellow, Department of Legal History, CASS Law Institute, and Dr. Huang Hai, Assistant Research Fellow, Department of Legal History, CASS Law Institute served as commentators at the lecture. In the lecture, Professor Gao Hancheng took the phenomenon of confusion between “extraterritoriality” and “consular jurisdiction” in China since modern times as the starting point to explain the need for a correct definition of the concept of “extraterritoriality”, gave a systemic and in-depth introduction to the evolution of this concept of “extraterritoriality” in modern history of vocabulary in light of the dual meaning of this concept in historical documents, and explored some issues of legal history as reflected in this evolution process.