Effeciveness, Opening, Flexibily, And Comfortability

21st century beginning, with advent of informational and digitized epoch, the Chinese starts to transform massively from the literature library to the digitized library; moreover the newly built library without exception must conform to the digitized requirement. Because the foundational transmission way of information of the library has been transformed, spatial constitution, layout way, function organization, and service pattern should have the revolutionary change.At the same time, 21 centuries which is more pay attention to take the human as the central is epoch of social full development, and it tries hard to create an ideal condition of "the harmonious society". Thus, the public library becomes one of important methods of dissemination of the science, the technology, the culture, the education and so on.From this, this article gripped tightly the clue of development and evolution of Chinese and foreign library. By means of consulting domestic and foreign material of library building and management literature and depending on the detailed source material in public library of Beijing, Shanghai, and Tianjin, the author has cleared off our country public library construction in each development stages. Unifies the development request of new century, the new characteristic of public library is elaborated: effectiveness, openness, flexibility, and comfortableness. In this foundation, the author has researched the overseas new development tendency of public library. According to compare with and profit from the massive overseas outstanding libraries, the author expects that these can assist and enlighten our country library at theory and practice project.