ENThis article is on a topic that has become very relevant in recent times regarding the preservation of cultural treasures - preventive conservation. It has a brief review of current trends in the standardisation of suitable conditions for protecting cultural treasures. Most attention goes towards the practical application of preventive conservation, and the monitoring and control of environmental conditions in the repositories of the Archaeological Collection of the National Museum - Palace of the Grand Dukes of Lithuania. The museum’s Archaeological Collection consists of around half a million artefacts recovered from archaeological investigation of the Vilnius Lower Castle territory. The archaeological artefacts, which have undergone several radical changes in their environmental conditions, are exceptional objects in terms of preventive conservation - they are often more sensitive to unsuitable storage conditions due to changes to their chemical structure that have taken place in the archaeological environment, as well as physical damage, than are historic exhibits made of the same materials. In order to preserve these artefacts in a good condition for as long as possible, many of them must undergo laboratory conservation procedures. Yet no less important is the storage of these cultural treasures both prior to conservation and afterwards. Particular attention must be given to the preventive conservation methods used in repositories and the control of environmental factors that cause damage. These are the museum’s spaces where a mąjority of the collections are kept for the longest period of time. The museum’s treasures kept in its repositories are inspected less frequently, so any damage is not noticed as soon as is the case with the cultural treasures on display in the museum’s expositions.