The invention provides an active radix gentianae component extracted from Chinese medicine radix gentianae. The active radix gentianae component is white, has pungent smell, and is easy to dissolve in chloroform, soluble in normal hexane and slightly soluble in alcohol and methanol. When TLC analysis is carried out, chloroform is used as a solvent, the Rf value of a 5-cm high forward silica plateis about 0.4, the sample can obviously absorb ultraviolet under 248nm to 320nm of wavelengths, and the content of the active component in dry radix gentianae roots and rhizomes is about 0.1%. The active radix gentianae component in the invention can be obtained by lixiviating an organic solvent, distributing a solvent and separating an open chromatographic column, has obvious similar nerve growthfactor activity, can promote the rebirth of neurons of the adult brain and prevent the regenerating function of the neurotrosis and the inhibitory nerve of beta-amyloid, and can be applied to preparing medicaments for preventing and treating neurodegenerative diseases such as hypoxic ischemia brain damage, senile dementia and the like.