A polyolefin based biaxially oriented multi-layer film having at least one surface layer comprise of the propylene-ethylene random block copolymer;The propylene-ethylene random block copolymer obtained through sequential polymerization catalyzed by a metallocene component which is composed of 30 to 70 wt % of a propylene-ethylene random copolymer component having an ethylene content of 1 to 7 wt % produced in the first step of the polymerization and from 70 to 30 wt % of a low crystallinity or an amorphous propylene-ethylene random copolymer component produced in the second step of the polymerization having an ethylene content of 6 to 15 wt % higher than that of the polymer component obtained in the first step, wherein that shows a single peak at 0.degree. C. or lower in the temperature-loss tangent (tan .delta.) curve obtained by dynamic mechanical analysis (DMA).