A film and method for fastening cargo during transportation wherein the film has a percentage strain change 100 hours after applying a load of 3.5 MPa at a temperature of 23 C. of not more than 2.0%, and a percentage strain change 100 hours after applying a load of 0.5 MPa at a temperature of 55 C. of not more than 2.5%. Moreover, it is preferable for the elastic modulus at a temperature of 23 C. to be not more than 60 MPa, and the elastic modulus at a temperature of 55 C. to be not more than 20 MPa. Such a film can be formed from substantially random interpolymer(s) each comprising 1 to 99 mol % of polymer units derived from an aromatic vinyl or vinylidene monomer and/or a hindered aliphatic or cycloaliphatic vinyl or vinylidene monomer, and 1 to 99 mol % of polymer units derived from at least one -olefin having 2 to 20 carbon atoms. The above film has a low percentage strain change compared with films made of EVA or a urethane resin, and hence the ability to hold/fasten products during transportation is excellent, and thus the products can be prevented from being damaged.