The blue-stain fungi in course of their development in wood may have an effect on wood structures and change of wood properties influenced on its use value. Investigation have been undertaken to clear the influence of blue-stain fungi on wood hygroscopicity and absorptiveness as indicators for the wood ability to impregnation with water diluted wood preservatives. The wet sapwood samples of fresh cut Scots pine (Pinus sylvestris L.) were infested with pure cultures of fungi: Ceratocystis penicillata (Grosm.)C.Moreau, Cladosporium herbarum Pers. ex Fries, Discula pinicola (Naum.) Petr. or their mixture and left exposed into their action through 1, 3 and 12 month period. The physical properties: hygroscopicity and absorptiveness of blue stained wood samples and their twin control samples were determinated and compared after each incubation period. The hygroscopicity of blue- stained wood amounted only to 1-2% more than this of control wood, but there was still such a tendency in different investigated periods of wood incubation with blue-stain fungi. The absorptiveness of the stained wood increased greatly particularly after 3 and 12 month of being infected by fungus or fungi. The mean increase of infected wood absorptiveness was great reaching several dozen percent more than control wood. Such differences showed on grater ability of blue-stained wood to impregnation with water diluted wood preservatives than control wood not infested by the blue-stained fungi.