In order to clarify the structure and phusical and chemical properties of the bark of Querczw nariabilis Blcme which were grown Chungbuk area (Korea), the virgin and reproduction corks were analyzed, and the results are as follows : 1. Cork structure : The cork tissue consists of cork cells, lenticels, sclerelds and dark-brown zone. From the microscopic observation, lenticels were found to be relatively rich in reproduction cork, and sclereids were in virgin one. In addition, the average ring widths of reproduction cork was wider than that of virgin, and the percentage of late cork was rich in virgin cork. Apart from difference between virgin and reproduction cork above mentioned, we have also observed over all detaile of the cork cells. The cork cells were longer in the radial direction, and the tangential faces of them were hexagonal shaped. The dimension of the hexagonal did not show any difference between early cork and late cork. The length(length in R direction) and the cell wall thickness of late cork cells were about one forth shorter and two times thicker than those of early cork, bat their was no difference between virgin and reproduction cork. It was observed that six lateral walls(except for two hexagonal walls) of a cork cell exhibited collugations along the radial direction, and the number of which per wall varied considerably(av. 2-3). As for the fine structure of cork tissues, X-ray diffraction analysis indicated that the crystallinity of cellulose in both virgin and reproduction cork was extremely low in comparison with a normal wood. 2. Physical properties Virgin cork has relatively higher density than reproduction cork. Cark absorbed same amount of water from each three section which is very lower compared to that in wood by rate of 1/33. It is expected that lenticel contents have an effect on water absorption of cork, and water absorption was more larger in reproduction cork with high lenticel content than in virgin cork. EMC was about 3 percent less in cork than in wood. but there was no difference between virgin and reproduction cork. Total shrinkage and swelling were larger in radial direction than in tangential and longitudinal directions, but there was no difference between virgin and reproduction cork. Caloric value was higher in cork than other harks and the virgin cork which has more alcohol-benzene extracts in its contents was higher than reproduction cork. The thermal conductivity in radial direction of cork was lower than that of wood and other barks by rate of about ⅓∼1/5, but there was no difference between virgin and reproduction cork. 3. Mechanical properties In compression test, the maximum strength was not found in three direction. The modulus of elasticity on compression was almost the same in longitudinal and tangential directions and they were higner than that of radial direction, Modulus of elasticity in virgin cork was higher than reproduction, in longitudinal and tangential directions : and in radial, reproduction showed higher modulus of elasticity than virgin. Tension strength was also almost the same in longitudinal and tangential directions, and there was no difference between virgin and reproduction cork. Brinell`s hardness of tangential section was above that of cross and radial sections, but there was no difference between virgin and reproduction cork. Even when compressed 0.1, both virgin and reproduction corks were almost recovered to the original dimension in three directions immediately after unleaded, and there was no difference between virgin and reproduction cork. 4. Chemical properties : 1%NaOH, alcoho-benzene extracts and ash contents of cork were similar to other barks, but cold and hot water extracts were less than wood. Lignin contents was less than other barks, but cellulose and holocellulose were similar to other harks. Suberin contents was less than cork of Qrsercus subev L.. In chemical composition, hot water extracts, pentosan and ash