Increasing concern over heavy metal contamination of the aquatic environment is urging the more effective and environmentally friendly methods of remediating heavy metals from contaminated waters. The use of plant materials as metal adsorbents may be a possible solution. In this study, wheat stems biomass has been utilized as bioadsorbent to bind lead(II) from aqueous solution. Selected binding conditions such as reaction time and solution pH were optimized. The effect of chemical modification on lead(II) binding capacity of the biomass was investigated. Results showed that the lead(II) binding process by wheat stems biomass is fast and the process is strongly affected by the solution pH. After esterification of the biomass, the lead(II) binding capacity decreased dramaticly, while the lead(II) binding capacity increased greatly after base hydrolyzation of wheat stems. FTIR spectra showed that hydroxyl groups and carbonyl groups in wheat stems biomass may play an important role in the binding of lead(II). In addition, XPS analysis also supports this explanation. These studies are useful for determining ligands that may involve in lead(II) ions binding by wheat stems, thus aiding in our understanding of the mechanisms involved in the removal of metal ions from contaminated waters through biosorption.