An extract of Xanthoceras sorbifolia Bunge, which comprises greater than 50 wt % saponin. Extraction of the extract of Xanthoceras sorbifolia Bunge and its uses in manufacturing medicaments for treating urinary incontinence and frequent micturition caused by senile dementia or bladder degradation, puerile enuresis, mental retardation for children, cerebral aging, middle-aged dementia and senile dementia, Parkinson's syndrome. Dosage forms include injection, tablet, capsule, soft capsule, oral solution or dripping pill.