Abstract: The present invention relates to a linear block copolymer and a process for preparing the same, particularly to a linear block copolymer and a process for preparing the same which can improve transmissivity of a block copolymer and remarkably lower a Haze value by introducing a vinyl aromatic hydrocarbon to conduct primary polymerization, simultaneously introducing a vinyl aromatic hydrocarbon and a conjugated diene monomer therein to conduct secondary polymerization, and introducing a vinyl aromatic hydrocarbon therein to conduct tertiary polymerization, thereby locating a conjugated diene/vinyl aromatic hydrocarbon copolymer block in a block copolymer.