The present invention provides a block copolymer composition comprising a block copolymer A represented by formula (A) and a block copolymer B represented by formula (B), the block copolymer composition having a water content of 200 ppm by weight or less when the block copolymer composition has been formed in a shape of pellets, dried, and allowed to stand at a temperature of 37° C. and a relative humidity of 70% for 24 hours. In the formulas, Ar1a, Ar1b, and Ar2b are aromatic vinyl polymer blocks having a weight average molecular weight of 6,000-18,000, Ar2a is an aromatic vinyl polymer block having a weight average molecular weight of 40,000-400,000, and Da and Db are specific conjugated diene polymer blocks. The block copolymer composition has a high modulus of elasticity, exhibits low tension set, and ensures that the formation of a hole is prevented when a film is formed by melt-forming the block copolymer composition. Ar1a-Da-Ar2a  (A) Ar1b-Db-Ar2b  (B)