NOVELTY - Extraction of high purity huperzine A and huperzine B from herbal medicine Phlegmariurus crutomerianus comprise extracting Phlegmariurus crutomerianus with acidic water, extracting twice with solvent; combining extract and filtering; absorbing filtrate on ion exchange resin for 30 minutes; eluting with liquid ammonia water; concentrating and extracting ; separating filtrate on reverse phase column chromatography; decolorizing with active carbon; and crystallizing and re-crystallizing to obtain pure huperzine A and huperzine B.    USE - Extraction of high purity huperzine A and huperzine B from herbal medicines Phlegmariurus crutomerianus.    ADVANTAGE - The method greatly increases basis for extracting huperzine A and huperzine B from new product. It has low requirement on environment, short separation time, and provides product with highest purity. The materials used are cheap and easy to obtain, separation is simple and easy to control, purification efficiency is high, and used reagents are nontoxic.    DETAILED DESCRIPTION - Extraction of high purity huperzine A and huperzine B from herbal medicine Phlegmariurus crutomerianus comprises crushing dry Phlegmariurus crutomerianus to 1-10 meshes and reserving; adding de-ionized water to obtain saturated acidic water having pH of 5; extracting twice with solvent having volume ratio of 10 folds and 8 folds of raw materials for 2 hours and 1.5 hours; combining extracts and filtering to obtain filtrate; coating filtrate on ion exchange resin and absorbing for 30 minutes; eluting with 3 BV column liquid ammonia water; concentrating and regulating pH to neutral and standing for 10 hours; filtering to obtain filtrate; concentrating until volume is 1/15 of primary volume; separating filtrate on reverse phase column chromatography; collecting liquid to obtain liquid 1 and liquid 2; extracting with mixed solution of ethyl acetate and petroleum ether at volume ratio of 1:1 to obtain raw product of huperzine A and huperzine B; adding 100-150 folds 80% ethanol to raw product of huperzine A and huperzine B; heating and fully dissolving; adding 0.1 folds weak acidic active carbon; intermittently mixing and decolorizing for 1 hour; filtering when it is hot; concentrating filtrate to volume of 1/15 of original volume; crystallizing for 8 hours and filtering to obtain raw crystal; adding 100-150 folds of 95% ethanol to raw crystal; heating and dissolving; concentrating to 1/15 and standing; separating white needle-shaped crystal; and filtering and vacuum drying to obtain huperzine A and huperzine B having purity of greater than 95%.