The relevance of the cognitive approach to the libraries and bibliography in the period of the society transformation from the information to the cognitive one is substantiated. Several trends in Russian and foreign studies of cognitive aspects of academic libraries activities are identified. The structure of library cognitive activities, their subjects and objects, processes, instruments and results are described. For the first time, based on the concept of cognitive activities, the author introduces the concept of the scientific library cognitive environment that is defined as an anthropogenic component of the library’s information space where cognitive objects and subjects are interacting and self-organizing being supported by cognitive infrastructure and related to information retrieval and processing, knowledge storage and preservation. The structure of the scientific library cognitive environment is defined based on the system of knowledge processes transformation; the environment components are intended for nonverbal transmission of implicit knowledge; conversion of implicit knowledge into explicit knowledge; distribution of bibliographic products; translation of explicit knowledge into the implicit form. The content and instrumental components of the cognitive environment are specified on account of cognitive objects. Specific features of the components are described. The author argues that there is the demand for developing librarian’s cognitive communications within the evolving scientific library cognitive environment and integration of librarians, being cognitive objects themselves, into the information technological Internet space. The article is sponsored by the RF Government (Order № 211 of March 16, 2013), Agreement № 02.А03.21.0011).