Polyacrylonitrile/silica nanospheres with three-dimensional interpenetrating network structure have been synthesized via emulsion polymerization method using 0.08 g azobisisbutyronitrile (AIBN) as initiator, 5 g acrylonitrile, and 5 g gamma-methacryloxypropyl trimethoxy silane as monomer, 0.85 g dodecylbenzene sulfate as emulsifier at 60 degrees C for 10 h. The composition and morphology of the obtained nanospheres were investigated by infrared spectrum, thermogravimetric analysis, and scanning electron microscopy, respectively. The obtained polyacrylonitrile/silica nanospheres were used to investigate adsorption Pb(II) from aqueous solutions. The research results display that composite material has high adsorption capacity at optimum pH = S. The maximum adsorption capacity was 0.108 mmol/g within 300 min at 25 degrees C. The pseudo-first-order equation and the pseudo-second-order equation are applied to analyze the experimental data. Adsorption behavior for Pb(II) onto nanospheres belongs to the pseudo-second-order kinetic model, and the adsorption process is a chemical process.