Abstract: The softwood of Cunninghamia lanceolata and Pinus massoniana were steamtreated at temperature 90℃ and 100℃. The hard wood of Nothofagus spp.and Toona sinensis were steamtreated at temperature 70℃ and 90℃ for 4 h and 8 h. The radial gas permeability and tangential gas permeability of the steamtreated specimens were compared with those of nonsteamtreated one. The results showed that the data of permeability were improved dramatically. Higher temperature could obviously promote the permeability of wood. The effects of steamtreated time on the permeability was slightly different.