AbstractThe chemical components of freeze‐dried stromata from Cordyceps scarabaecola were examined. The stromata consisted of crude carbohydrates (55.1%) and crude proteins (14.2%). The stromata were also composed of a low content of crude ash (6.6%) and fat (1.5%). The composition of the carbohydrate in the stromata included a large quantity of glucose (46.6%), mannose (35.4%) and galactose (18.0%). The acidic amino acids such as glutamic acid (32.1 mg/g) and aspartic acid (24.7 mg/g) were present in a large quantity. The extracts of stromata did not reveal any inhibitory activity for AChE in vitro. It was observed that a hot‐water extract (HW) of the stromata contributed significantly to the anticoagulant activity (60 s coagulating time) and anticomplementary activity (62% of ITCH50 value). The MeOH‐soluble fraction (M) from the freeze‐dried stromata inhibited TPA‐induced O2− generation as effectively as the positive control, genistine 27%. The hot‐water extract (HW) showed the most potent intestinal immune system modulation activity and the MeOH‐soluble fraction (M) had intermediate activity. Copyright © 2003 John Wiley & Sons, Ltd.