The article analyzes the results of consistent monitoring of the state of preservation of collection of manuscripts and document sfrom the Shevchenko Scientific Society Library in Lviv, which are now stored in the V. Stefanyk LNNBU. Сonducted a comprehensive analysis of the key areas of formation of the NTSh Library fund and the results of qualimetric research in the field of preservation of its manuscript heritage. On the basis of studying the state of preservation of the manuscript fund and processing the results of qualimetric research, the analysis of the operational state of the whole collection and each specific storage unit in particular was carried out. In order to study the ecological and physical condition of the exceptionally valuable archival fund of the Library, a survey of manuscripts and documents from the fund of the Library of NTSh was performed. The safety of stock units has been studied using a modified qualimetric method, which allows you to analyze the performance of documents. The method consists in organoleptic research and assessment of physical safety of material components of manuscripts. It is established that the manuscript fund of the NTSh Library consists of documents created at different times, which are different in terms of material basis and with different degrees of preservation. Active use, the destructive effects of the environment, anthropogenic and natural factors have led to the deterioration of their condition. Qualimetric examinations of documents 14 – 18, 18-19 centuries. Fnd the data obtained during the analysis of the state of preservation of documents showed that the documents of good preservation in this part of the collection is less than 15%. More than 45% of medium-preserved documents, which require minor conservation and restoration interventions, and almost 40% of valuable manuscripts are low-preservation documents and require more complex restoration operation. The results of the study, obtained during the monitoring of the physical condition of the manuscript fund of the NTSh Library, will allow to plan and implement methods for the return of written monuments of operational properties, their further use and study by a wide range of scientists. For the first time surveys of the manuscript fund of the NTSh Library allowed to determine the necessity and priority of preventive and operative conservation and restoration measures for specific written monuments. The information obtained will help to plan and optimize the approach to the implementation of restoration processes at various sites. Keywords: NTSh library, storage, manuscripts, conservation, monitoring, qualimetry.