There is disclosed a novel composite film prepared by melt extrusion laminating a polymer blend composition comprising a low-crystalline resin of an ethylene-butene copolymer and a polyolefin resin having incorporated therein a lubricant and an anti-blocking agent onto a surface or surfaces of a uniaxially stretched polypropylene film followed by stretching the laminate film in the direction perpendicular to the direction in which said polypropylene has been stretched and optionally subjecting the resulting film to corona discharge treatment. The composite film thus made provides an excellent packaging material because of its improved antistatic, lubricating and anti-blocking properties in addition to its heat sealability feasible at lower temperatures than prior art materials.