[Penggunaan ruang bawah tanah sebagai alternatif akibat terbatasnya tanah di kota-kota besar. Penelitian secara yuridis normatif, yang bersifat eksplanatoris, dengan analisis kualitatif. Pemanfaatan ruang bawah tanah untuk keperluan usaha di bawah Terminal Blok M menurut Hukum Tanah Nasional serta pemberian hak atas penggunaan ruang bawah tanah oleh PT Langgeng Ayomlestari kepada pihak lain. Hukum Tanah Nasional tidak mengatur secara tegas mengenai penguasaanruang bawah di tanah yang berdimensi tiga, sehingga pemberian ruang-ruang di bawah tanah Hak Pengelolaan untuk keperluan usaha tidak tepat. Dibutuhkan suatu lembaga hak baru yaitu Hak Guna Ruang Bawah Tanah dan Hak Milik atas Satuan Rumah Susun;The use of underground space as an alternative due to limited ground in large cities. This is the normative judicial research, eksplanatoris, and dataanalysis in qualitative. The utilization of underground space under the Blok M Terminal for the commercial use reviewed based on National Land Law, and the granting of the using underground space rights by Limited Liability Company Langgeng Ayomlestari to other parties. National Land Law does not regulate about the use of underground specifically, which is three dimensional so that the granting of the using underground below Hak Pengelolaan land for commercial use is inappropriate. Need specifically regulation to use basement, The use of underground space as an alternative due to limited ground inlarge cities. This is the normative judicial research, eksplanatoris, and dataanalysis in qualitative. The utilization of underground space under the Blok MTerminal for the commercial use reviewed based on National Land Law, and thegranting of the using underground space rights by Limitesd Liability CompanyLanggeng Ayomlestari to other parties. National Land Law does not regulateabout the use of underground specifically, which is three dimensional so that thegranting of the using underground below Hak Pengelolaan land for commercialuse is inappropriate. Need specifically regulation to use basement]