Chitosan is a natural polymer that has many physicochemical(polycationic, reactive OH and NH2 groups) and biological(bioactive, biocompatible, and biodegradable) properties. In this study, chitosan nanoparticles were prepared using poly-γ-glutamic acid(γ-PGA) as gelling agent. Nanoparticles were formed by ionic interaction between carboxylic groups in γ-PGA and amino groups in chitosan. Chitosan(0.1~1 g) was dissolved in 100 ml of acetic acid (1% v/v) at room temperature and stirred overnight to ensure a complete solubility. An amount of 0.1 g of γ-PGA was dissolved in 90 ml of distilled water at room temperature. Chitosan solution was dropped through needle into beaker containing γ-PGA solution under gentle stirring at room temperature. The average particle sizes were in the range of 80~300 nm. The prepared chitosan/γ-PGA nanoparticles were used to examine their removal of several heavy metal ions(Cd2+, Pb2+, Zn2+, Cu2+ and Ni2+) as adsorbents in aqueous solution. The heavy metal removal capacity of the nanoparticles was in the order of Cu2+ > Pb2+ > Cd2+ > Ni2+ > Zn2+.