A new way was used to chemically synthesize a series of novel complexes of heteroaromatic polymer-connected SWNTs and metal ions (Fe2+, Nd3+). These derivations of SWNTs were characterized by Fourier transform infrared instrument (FTIR), elemental analysis (EA), the transmission electron microscopy (TEM), thermogravimetric analysis (TGA) and Raman spectrum, and better regularity is shown. Moreover, the magnetic behavior of these polymeric complexes was measured as a function of temperature (0-300 K) and as a function of magnetic field strength (0-40 kOe) at 5 K. The results of measurements indicate these complexes have special soft-ferromagnetic properties. (C) 2003 Elsevier B.V. All rights reserved.