Тhe article is devoted to the legal content of the notion of the «sustainable city», and also reveals the public relationships, regulated by the legal norms, which develops concerning its functioning, as the relevant subject of the modern complex legal regulation. Investigates the particular qualities of the ecological component of such juridical categories as «favorable habitat», «improving the quality of life of the citizens» and «sustainable urban development» as the characteristics of sustainable cities which is considered as a human habitat and a special ecologically compatible socio-cultural area. The existence of general public interest and the necessity in the balanced combination of private and public interests in the sustainable process of urbanization as the global and systematic process is justified.