The concept of library is newly interpreted and designed under the environment of U-City. The basic notion of the library should not changed its kernel nevertheless, the new technologies like ubiquitous computing services are applied to the library, which functions in terms of information services, continuous learning programs and communities of practice(CoP). The library is fit for any technologies or environments as organism. Actually the library has been shown in terms of new information technologies with the changes of the times. It leads to comprehend the library as its appearance not as it is. The libraries including even cities have evolved toward ubiquitous(computing) environment. On the other words, the libraries have sought ubiquitous at the past, now they are still chasing it.