Cholesterol, cholest-5-en-3β-ol-7-one, cholest-5-en-3β, 7α-diol, cholest-5-en-3β, 7β-diol, cholesterol esters, p-hydroxybenzaldehyde, uracil, uridine, hypoxanthine, nicotinic acid, creatinine and urea were isolated from the pilose antler of Cervus (Sika) nippon TEMMINCK var. mantchuricus Swinhoe, along with fatty acids, triglycerides and monoglycerides. The amounts of hypoxanthine having an in vitro monoamine oxidase-B inhibitory activity, in the water, 50% EtOH and 70% EtOH extracts were determined by high-performance liquid chromatography.