Bovine serum albumin (BSA) was utilized to assemble with the binary complexes of poly(vinylpyrrolidone)-graft-poly(2-dimethylaminoethyl methacrylate) (PVP-g-PDMAEMA)/DNA formed by layer-by-layer electrostatic interactions to screen the residual surface positive charges of complexes.The coating of BSA was able to decrease the zeta potential of binary complexes nearly to electroneutrality without interfering with DNA condensation ability.The ternary complexes of BSMPVP-g-PDMAEMA/DNA demonstrated lower cytotoxicity compared with the binary complexes and also maintained high gene transfection efficiency in HepG2 cells.