Novel phenanthrimidazole-derivated magnetic nanoparticles were synthesized originally. The chemical compositions of the hydroxy-, chloro-, carboxy-ended phenanthrimidazole derivatives were proved by FT-IR and 1H-NMR spectroscopy and the pipe-like morphology was evaluated by SEM. The chemical compositions, morphologies and magnetic measurements of the magnetic nanoparticles were evaluated by FT-IR spectroscopy, TGA/DSC, XRD, TEM and VSM. The resulting products are spherical and aggregated by the magnetism of iron oxide, but dispersed individually in ethanol/water mixture.