Abstract: A silica based cross linking chitosan grafted with 4, 4 '-dihydroxychalcone( D-Chitosan@Si) was designed and prepared for selective separation and enrichment of flavonoids. The factors which affect the adsorption capacity of D-Chitosan@Si and the absorption mechanism were discussed in detail. The experimental results showed that the adsorption of Quercetin on D-Chitosan@Si was described by the Langmuir model,and the adsorption followed the pseudo second order kinetics equation,was controlled by multiple. D-Chitosan@Si was also successfully used to separate the flavonoids of tussilago farfara,the absorptive capacitythe of flavonoids was 52.31 mg/g and the purity was increased from 18.9% to 85.6%. It indicated that D-Chitosan@Si had high selectivity on enrichment flavonoids.