With mesoporous silicon as carrier material and APTES as modifier, the modified mesoporous silica sphere was successfully prepared. Its microstructures were characterized by transmission electron microscope(TEM), energy dispersive x-ray Detector(EDX) and Fourier transform infrared spectrum(FI-TR), and its adsorption on the heavy metal Pb was investigated. The results indicated that the APTES was grafted onto the surface of the mesoporous silica successfully, the modified mesoporous silicon had a selective adsorption characteristics on heavy metal Pb2+, and the adsorption capacity showed improving as the increase of the APTES in reactant.