This study was carried out to investigate the reasonable condition for better dimensional stability in woods by polyethylene glycol(PEG) treatment. Eight species grown in Kangwon-do were used for this study. Three species of softwoods(Pinus densiflora, Pinus koraiensis, Larix kaempferi) and two species of hardwoods(Prunus sargentii, Populus tomentiglandulosa) treated with 30% aqueous solution of PEG 1000 showed good dimensional stability under the treatment for 1 day. The dimensional stability of Betula davurica, Quercus mongolica and Quercus variabilis woods increased with increasing treatment time. From the above results, it was concluded that PEG penetration and dimensional stability were affected by characteristics of wood species such as density and structure.