Surfaces of natural sand particles were modified with (3-chloropropyl) trichlorosilane, so that bridging groups were introduced on the surfaces of natural sand particles;By grafting polyacrylonitrile onto the modified surfaces of the natural sand particles, a novel polyacrylonitrile/natural sand composite material was prepared from the acrylonitrile, the azobisisobutyronitrile, the divinylbenzene and the modified natural sand particles, which are as functional monomer, initiator, either skeleton monomer or cross-linking agent and carrier respectively;the composite materials were characterized by using infrared spectroscopy and scanning electron microscopy;On the FTIR spectrum, the main characteristic peaks of various functional groups including nitrile,benzene ring,and silicon hydroxyl, which were from functional monomer, cross-linking agent and carrier respectively, were observed. On the SEM, two different cross section morphologies having different density which were from acrylonitrile and modified sand particles were observed;This proved that the polyacrylonitrile was decorated on modified sand particles during our preparation process. After preparing the composite materials, micro-column of separation and preconcentration was prepared using the composite materials as filler;the adsorption of some toxic heavy metal ions onto the composite materials was observed by flame atomic absorption spectrometry (FAAS);The results show that the adsorption of Pb2+ onto the composite materials was more stronger than the absorption of other toxic heavy metal ions, therefore, in this paper, the adsorption of Pb2+ onto the composite materials was mainly studied,at room temperature, when pH and flow rate of solution were 5.4 and 4 mL·min-1 respectively, the trace Pb(Ⅱ) ions could be quantitatively adsorbed onto the composite materials;the maximum adsorption capacity of Pb(Ⅱ) on the composite materials can reach 62.9 mg·g-1. the column was eluted by 0.5 mol·L-1 HCl and recovery of Pb(Ⅱ) was more than 96%.