Fusogenic liposomes (virosomes) consisting of Sendai virus envelope proteins have been utilized for in vitro and in vivo genetic modification of animal cells. In this study, the virosomes containing DNA were prepared by quantitative reconstitution of Sendai envelope proteins, fusion protein and hemagglutinin-neuramindase in liposomal vesicles. The Sendai virosomes more efficiently transferred genes into cultured 293 transformed kidney cells than 1,2-dioleoyl-3-(trimethylammonium) propane-based cationic liposomes. At 200:1 weight ratio of envelope protein and lipid, the virosomes exhibited the best efficiency of gene transfection into the cells. The Sendai virosomes required relatively a short period of incubation time and much less cytotoxic, compared to the cationic liposome/DNA complex. The transfection efficiency of the Sendai virosomes containing DNA was maintained 70% after a month. This type of Sendai virosomes is relatively convenient for preparation and storage, compared to fusogenic liposomes prepared by liposome-virus fusion. First of all, because the constituents are quantitatively formulated, this type of virosome formulation can provide further consistent transfection for gene therapy.