A novel vector for gene delivery was synthesized. Here the ovalbumin (OVA) acts as a core and low-molecular-weight PEI600,vas grafted to its surface. The finally product was characterized (H-1-NMR, UV, and TGA) and its biophysical properties such as DNA condensing, particle size, and zeta potential were determined. The agarose gel assay indicated that OVA-PEI600 could efficiently condense plasmid DNA. Its particle size was about 150 nm and zeta potential was around +20 mV. The MTT assay showed that the cytotoxicity of OVA-PEI600 was less than PEI25 kDa. Its transfection efficiency in SKOV-3 and HepG2 cell lines was higher than that of PEI600 and comparable to PEI25 kDa. hi vivo, luciferase activity could be tested in liver, spleen, kidney, lung, and blood serum, respectively, in mice. The core-shell structure of OVA-PEI600 provided a novel strategy for nonviral gene delivery. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 114: 3744-3750, 2009