Chitosan, as a natural polysaccharide, has reactive amino and hydroxyl groups in its linear polyglucosamine chains, can be used to functionalize and modify. However, conventional modification method using single chitosan crosslinking with glutaraldehyde generally leads to decrease of functional groups (–NH₂–) and loading capacity, it's interested to prepare multifunctional chitosan-X  which used in many applications such as water treatment  by using diethylenetriamine pentaacetic acid (DTPA) with sufficient number of carboxyl groups on the backbones, is a commonly used as chelating agent for heavy metal. The preparation of modified chitosan investigated by IR, XRD, SEM and also mechanical properties which determined the comparative and competitive adsorption of some metal ions from aqueous solutions. Kinetic and thermodynamics of single system were  studied.