Abstract: Objective：To evaluate transfection efficiency of galactosylated poly(ethylene glycol)-graft-polyethylenimine (Gal-PEG-PEI) as a nonviral gene carrier of hepatocyte-targeting plasmid siRNA(psiRNA) in human fetus liver cells L-02 cells. Methods：The characteristics of the Gal-PEG-PEI/psiRNA nanoparticles were measured by dynamic light scattering. The transfection experiments were performed with the Gal-PEG-PEI/psiRNA using GFP as the reporter gene in L-02 cells and the transfection efficiency was evaluated by flow cytometry after 48h. The competition assay was carried out to confirm the uptake of Gal-PEG-PEI /psiRNA by ASGP-R in L-02 cells by adding 1mg galactose into the transfection media. Results：The results indicated that the particle sizes decreased with increasing charge ratios of Gal-PEG-PEI to psiRNA and had a minimum value around 81.1nm at the charge ratio of 20. The transfection efficiency of Gal-PEG-PEI was higher than that of PEG-PEI or naked psiRNA in L-02 cells. When galactose was added, the transfection efficiency of Gal-PEG-PEI was drastically decreased from (20.37±0.92)% to (4.84±2.12)%. Conclusion：The Gal-PEG-PEI nanospheres display perfect hepatocyte-targeting ability and can be potentially used as a nonviral gene carrier in liver diease therapy.