The article objective is to review theoretical and methodological problems of the library collection formation in accordance with national standards (GOST R 7.0.93-2015) requirements: optimization of technological processes for acquisition, registration, organization of library collections through the use of modern technologies, to upgrade the terms system relating to holdings. The work set and solved the following tasks: defining the library collection object; correlating notions of «the Russian Federation library fund» and «the national library fund»; analyzing the library collections grouping by a functional purpose; considering its modeling, basic principles of acquisition, distribution features; pointing reasons to exclude documents of the library collection; showing indicators to characterize the library holdings state. The library collection formation is considered as a series of successive processes and operations aimed to transform the documents amount in an orderly and systematic set (library fund). For the first time funds of a separate library are divided by functionality: custom funds designed specifically to serve users; technological funds used to maintain the user collections functioning, which are not included directly in library and information services. Stocks allocation is referred to activities on spatial ordering of documents in specially equipped premises - depositories, servers and/or other storages. Allocation of a local network of electronic documents is carried on servers and/or other electronic library repositories and organized by software and hardware. A detailed analysis of such complex library actions as documents exception, redistribution, and exclusion of the library fund is given