Abstract: In this work, amphiphilic copolymers were obtained by modifying hyperbranched polyethylenimine with methoxypolyethylene glycols. The utility of a multifunctional delivery vector comprised of antibody-polyethyloxide-polyethylenimine loaded with superparamagnetic iron oxide (Ab-PEG-PEI-SPIO) was investigated. The Ab-PEG-PEI-SPIO is capable of combining plasmid DNA into nanoparticles with diameters about 96nm (Ab-PEG-PEI-SPIO/pDNA complexes). The experiment results in vitro shows that the Ab-PEG-PEI-SPIO complexes transfect T-cells with high efficiency. The results of targeting group suggest that PEI-PEG possess the potential of combining application in gene delivery and MRI diagnosis.