The invention provides a method of manufacturing polyolefin-polyamide resin composition, which method has a large amount of discharge and is capable of long-time running and excellent in productivity. The method of manufacturing polyolefin-polyamide resin compositions comprises melting and kneading, extruding, and drafted drawing or rolling (a) a polyolefin, (b) a polyamide, (c) a silane coupling agent, (d) a first antioxidant with a melting point of 70-170° C., and (e) a second antioxidant with a melting point of 180-300° C. to disperse the polyamide (b) in the form of fiber with an average fiber diameter of 1 μm or less in the polyolefin (a) to finish the composition in the form of pellets.