This textbook on the Green City examines urban nature as an ideal, provider of services and conceptual urban design approach. It answers important contemporary questions that arise about the ecological and cultural interactions, development and structure, and ecological performance of urban nature worldwide. The book explains what urban nature is, how it came to be, and how it evolved in the context of the natural and cultural conditions of its sites. It also describes what constitutes urban biodiversity and the role of differentiated urban nature in the Green City concept. Theories of urban development and ecology are linked to practical applications of urban planning and illustrated with many case studies and examples. The great potentials of urban nature are shown in detail. In order to cope with or mitigate problems in the city, a targeted urban nature management adapted to the specific conditions of the different types of urban nature is needed, which includes nature conservation as well as nature design, always keeping in mind the relation to the urban dwellers. The textbook is especially addressed to students and teachers of urban planning, ecology, geography, social sciences as well as practitioners of urban design and nature conservation. This book is a translation of the original German 1st edition Die Grne Stadt by Jrgen Breuste, published by Springer-Verlag GmbH Germany, part of Springer Nature in 2019. The translation was done with the help of artificial intelligence (machine translation by the service DeepL.com). A subsequent human revision was done by the author primarily in terms of content and scientific terms, so that the book will read stylistically differently from a conventional translation but without loss of messages. Springer Nature works continuously to further the development of tools for the production of books and on the related technologies to support the authors.