Abstract: Pueraria flavonoids particles were prepared by using pueraria flavone as core materials. Particles walls were prepared by chitosan and sodium tripolyphosphate (TPP) . The pueraria flavone were added to the chitosan solution and this was added drop wise to the sodium tripolyphosphate solution while stirring, then freeze drying. Encapsulation efficiency was used as the main evaluating index, decide the optimum composition of particles walls. Its appearance was observed by SEM and XRD, and its release properties were analyzed. The optimum composition of nanoparticles:pueraria flavone 6mg/mL, chitosan solution 0. 6% (m/v) , TPP 0. 6% (m/v) . The encapsulation efficiency reached to 67. 1%. Pueraria flavonoids nanoparticles in vitro released slowly and completely. The release rate reached to 90% in 12h improving the rate of biological utilization. Pueraria flavonoids particles were prepared successfully by this way as expected.