A pharmacological composition including a component having pressure reductive activity obtained from Mycoleptodonoides aitchisonii fruit body which is safe and cheap, harvested constantly year-round by artificial cultivation, with equal quality, and useful for prevention and/or amelioration of symptom of hypertension caused by angiotensin I converting enzyme or the like. The invention also includes foods or beverages containing the pharmacological compositions, and methods of preventing or treating hypertension by administration of the composition.