The caterpillar-shaped Chinese medicinal mushroom (DongChongXiaCao) looks like a worm in the winter and like a grass in the summer. The fruiting body has been regarded as popular folk or effective medicines used to treat human diseases such as asthma, bronchial and lung inflammation, and kidney disease. The fruiting bodies of Paecilomyces tenuipes that formed on the living silkworm (Bombyx mon) host were used in this examination. This study was carried out to investigate the proximate composition, soluble sugar, amino acid and fatty acid profiles, and contents of the bioactive ingredient including adenosine and D-mannitol in the fruiting-bodies. The moisture content was 57.56%. Soluble sugars found were glycerol, glucose, mannitol and sucrose, and the contents exceeded $24;mgg^{-1}dry$ weight. Total free amino acid content was $17.09;mgg^{-1}dry$ weight. Arginine, glycine, proline and tyrosine were main amino acids. The content of oleic acid in fatty acids was high. Adenosine was more abundant in fruiting bodies than corpus.