Abstract: [Purpose/Significance] Based on the research of library transformation from the mode of "high-speed growth" to "high-quality development", this paper addressed the green development as one of the key routes for the transformation of public libraries and provides a multifaceted definition of green development and sustainability from home and abroad as applied to public libraries. [Method/Process] By investigating the transformation and development of domestic libraries in recent years and drawing on the experience from a range of international projects, this paper found out how dedication to be sustainable and green action has become more central and widespread in the library sector worldwide. Successful examples were drawn from IFLA Green Library Award as well as other innovative programs, services, buildings and projects based on increasing consciousness around the green development. This paper integrated an overview of various efforts to define the green library and arguements for sustainable libraries. At the same time, some typical examples of libraries' environmental awareness and sustainability have been presented. [Results/Conclusions] This paper puts foreword the key areas to implement the concept of green development in libraries, including library buildings, facilities and equipment, collections, information services, operational management as well as library strategic development plan, thus incorporating the library development in the scope of environmental, economic and social sustainability. Libraries should take into account the environmental impact of their building as well as their own activities. They should also consider their specific features, not just the criteria for green buildings and offices. Besides, they can promote recycling and sharing in the community in various ways. These actions can raise environmental friendliness as a value and signals the importance of environmental issues to the community. In the aspect of resource development, the basic task of libraries is to ensure open and easy access to reliable information, which includes environmental information. With the provision of information, libraries should also promote the information retrieval skills of the community in order to improve the information literacy of the public with regard to environmentally sustainable awareness. In conclusion, libraries should create an environmental strategy that defines the means and objectives of the environmental work. It is important to raise awareness of the role public libraries can play in the near future, showing proof of their contribution to UN 2030 Agenda and SDGs by measuring and gathering evidence of their performance, namely the access to information and knowledge, access to information infrastructures as well as literacy competences development.

Key words: high-quality development, green development, sustainable development, public library