Under the influence of the revolutionary development of telecommunications and the informative technology, basic changes have occurred in the activity of the parliamentary Libraries. New technologies and modified requests of the users have lead into transformation of the modern parliamentary libraries from ordinary collectors and keepers of printed materials to Centers that undertake different types of researches and analysis for the needs of Parliaments for which they are linked. The description of elementary characteristics of modern parliamentary libraries and trends of their further development are given in the paper.