Chitosan nanoparticles (CS NPs) was prepared by mixed with TPP for drug release carrier in this study. Generally, Chitosan is a good and non-toxic biodegradable polysaccharide polymer with low immunogenicity. Tripolyphosphate (TPP) is a polyanion, and can interact with cationic chitosan by electrostatic forces. So Chitosan/TPP nanocomposites were synthesized Berberine, a naturally occurring isoquinoline alkaloid, was shown to have anti-inflammatory and anti-tumour properties in vitro systems. And we have used the transmission electron micro-graphs (TEM) and Dynamic light scattering (DLS) to gain the CS nanoparticles’ size. The action of tripolyphosphoric groups of TPP crosslinked with ammonium groups on chitosan in the nanoparticles and it was identified by FTIR. We also obtained the poison property of berberine mantled by CS NPs to human breast cancer cell.