Liposomes of pSV-β-Galactosidase vector plasmid DNA with various lipid composition were prepared by the thin-film method. Size distribution, shape and the efficiency of plasmid DNA encapsulation were investigated. Effect of sonication time on the plasmid DNA entrapment in liposomes and stability at 4℃ were also examined. Sizes of neutral liposomes were about 100-200 nm and above 1 ㎛, and those of cationic liposomes were about 400-600 nm and above 1 ㎛. Shapes of liposomes entrapped plasmid DNA were spherical. Proper sonication time for better entrapment was below 15 minutes and stability at 4℃ was decreased rapidly after 1 day. Plasmid DNA entrapments of complex liposomes of various lipids were higher than those of liposomes made from one sort of lipid. Plasmid DNA entrapments of cationic liposomes were higher than those of neutral liposomes.