Abstract: Physical and chemical determinations were made on the PEG treated wood samples [Cunninghamia lanceolata (Lamb.) Hook.) and Pinus massoniana Lamb.] taken from ancient shipwrecks, and they were compared with the untreated wood of the same spieces. Experements showed that PEG may meet almost all the requirements in the preservation of ancient wood. It was concluded that PEG treatment is the most practical and effective way to preserve ancient wood. In view of mains taining anti-shrinkage efficiency and humidity resistance of ancient wood. PEG 4,000 proved to be better.