An ethylene based polymer composition comprising the following component (A) and the following component (B) wherein the content of the component (B) is 0.5 to 20 parts by weight per 100 parts by weight of the component (A): Component (A): an ethylene based polymer satisfying all of the following requirements (a1) to (a3): (a1) the density is 890 to 925 kg/m3, (a2) the melt flow rate (MFR) is 0.1 to 10 g/10 minutes, (a3) the flow activation energy (Ea) is 50 kJ/mol or more, Component (B): an ethylene-α-olefin copolymer satisfying all of the following requirements (b1) to (b3): (b1) the density is 890 to 925 kg/m3, (b2) the intrinsic viscosity [η] measured in a tetralin solution is 4 to 15 dL/g, (b3) the flow activation energy (Ea) is less than 50 kJ/mol.