A wrapping film and shrink film which are formed from a resin composition comprising a 1−butene polymer satisfying the following requirements (1) to (4) and an olefin polymer. It is a crystalline resin having a melting point (Tm−D) as measured with a differential scanning calorimeter (DSC) of 0 to 100°C (provided that this "melting point" is defined as the peak top of the peak observed on the highest−temperature side in a melting endothermic curve obtained by holding a sample in a nitrogen atmosphere at −10°C for 5 minutes and then heating it at a rate of 10 °C/min). The stereoregularity index {(mmmm)/(mmrr+rmmr)} is 20 or lower. The molecular weight distribution (Mw/Mn) as determined by gel permeation chromatography (GPC) is 4.0 or lower. The weight−average molecular weight (Mw) as determined by GPC is 10,000 to 1,000,000.