Epigallocatechin-3-gallate (EGCG), a principal polyphenolic, which is most abundant and active component in tea. It is considered key to these healthful qualities. However, EGCG used in clinical application which is still shortcomings of short half-life and low bioavailability. Chitosan (CS) has been widely used in pharmaceutical and medical areas, particularly for its potential in the development of controlled release drug delivery systems due to its well properties. In this study, we prepared EGCG-loaded chitosan nanoparticles by ionic polymeric method using sodium tripolyphosphate(TPP) as ionic polymeric agent successfully. Results controlled conditions (concentration of CS, 2 mg/mL; pH = 5.4; volume of TPP(0.5 mg/mL), 6.6 mL; amount of EGCG, 15 mg; ionic polymeric time, 24 h at room temperature (0.5 mL/min))volume of TPP(0.5 mg/mL), 6.6 mL; amount of EGCG, 15 mg; ionic polymeric time, 24 h at room temperature (0.5 mL/min)) for entrapment efficiency, loading efficiency, mean particle size and Zeta potential, were found to be 62.3 %, 33.8 %, 141.5 ± 0.4 nm and -31.21 ± 0.54 mV, respectively, and CS-EGCG-NPS have well property of sustained release.