A polyolefin composition, which comprises: (A) 1 to 99% by weight of a polyolefin having the following properties of (a) to (e); (a) a ratio of kinematic viscosity .eta..sub.1 at a frequency of 10.sup.-1 rad/sec to kinematic viscosity .eta..sub.2 at a frequency of 10 rad/sec at a temperature of 190.degree. C. according to a kinematic viscoelasticity determination method of 4 to 20, (b) a crystallization peak temperature Tcp according to a Differential Scanning Calorimetry of 110.degree. C. to 130.degree. C., (c) a ratio (Tmp/Tcp) of melting peak temperature Tmp to crystallization peak temperature Tcp according to a Differential Scanning Calorimetry of 1.1 to 1.5, (d) Tmp/(Tmp-Tcp)=3.0 to 9.8, and (e) a crystal structure exhibiting a-axial orientation in a diffraction pattern according to a X-ray diffraction method, and (B) 99 to 1% by weight of a propylene resin having the following properties of (f) and (g); (f) a ratio of kinematic viscosity .eta..sub.1 at a frequency of 10.sup.-1 rad/sec to kinematic viscosity .eta..sub.2 at a frequency of 10 rad/sec at a temperature of 190.degree. C. according to a kinematic viscoelasticity determination method of below 4, and (e) and no crystallization structure exhibiting a-axial orientation in a diffraction pattern according to a X-ray diffraction method.