The booming of three-dimensional (3D) land use brings a change of the connotation of land rights, which will expand “flat” 2D land legislation with 3D land legislation. The legal issues of urban underground space for 3D objects in large cities around the world have been attracting more and more attention. A supportive legal framework is crucial for underground space utilization in a country. This paper analyzes the present 173 representative laws and regulations of urban underground space utilization and management of China from 1998 to 2018, and attempts to interpret the current laws and regulations of underground space from four aspects; by quantity, spatial distribution, legislative force and content. The result shows that poor legal framework of urban underground space in China, including low-level of legislative force, disunity of local legislation standard and absence of special statutes and regulations, are the main reasons causing ownership disputation, registration chaos, as well as no unanimous judicial practice. To address these issues, the paper refers to a case study for underground space legal framework in Japan and aims to form a set of top-down unified legal framework, including basic law, special statutes and regulations, as well as supplementary policies and documents of urban underground space, and proposes that the underground space planning should be incorporated as one essential portion of the master planning in China. By studying the legal system of underground space in Japan and China, this study may offer better insight for those conducting UUS legal framework research as well as serve as reference for countries with similar legal issues.