By air drying and by the Japanese "one hundred degree research method", the drying characteristics of four species of hard-wood including CyclobalanIopsis delavayi, Catanopsis delavayi, Lithocarpus dealbatus and Quercus variabilis were studied. The results indicated that because of the low rates of drying and easy occured drying defects, such as the surface check, the honeycomb check, the warping and twisting, the wood of these four species are hard to dry. The reasons include high tyloses contents in vessels, high wood density, uneven wood structures, high volumetric shrinkage values, high ratio of tangential to radial shrinkage and poor water permeabilities for these four kinds of wood. Suggestions were made to overcome these drying defects above mentioned and the drying schedules of these four species were built.