We newly developed an indoor cultivation technique for Wolfiporia cocos (WOLF) RYVARDEN et GILBERTSON (Syn. Poria cocos WOLF), not with soil, but using mushroom culture bottles with pine logs, and clarified some cultural characteristics of sclerotia in the laboratory. To determine the optimum conditions for sclerotia growth, the weight of sclerotia and concentration of CO₂ in three different air filters; cloth, paper and urethane resin, and closed bottles were tested. When the cloth air filter was used, the growth rate was the fastest and the yield was maximal. These results suggested that the aeration was an important environmental factor for cultivation. To clarify the characteristics of culture in the cloth air filtered and closed bottles, the weight of sclerotia, the compositions of pine logs and the contents of pachymic acid and dehydropachymic acid were examined during 24 weeks. The growth of scleroia and the wood decaying efficiency in the cloth air filtered bottles were better than those in the closed bottles. Also, it was found that W. cocos was a brown rot fungus due to the alkaline solubility of pine logs in the wood decay process. In addition, the contents of pachymic acid and dehydropachymic acid and the TLC pattern between the cultivated and commercial sclerotia did not differ remarkably.