The temperature-dependent molecular chains movements and transitions of polystyrene-block-poly(ethylene-co-1-butene)-block-polystyrene block copolymer (SEBS) above room temperature was studied by in-site infrared spectroscopy combined with moving-window two-dimensional (MW2D) correlation spectroscopy. Some complex molecular chains movements and transitions of SEBS revealed with a linear increment temperature increasing (30-166oC). The extraordinary weak crystalline of -(CH2-CH2)-n of poly(ethylene-co-1-butene) block (EB) melts at 48oC. The heat enthalpy relaxation of polystyrene block (S) of SEBS, which is induced by the framework movement of the side benzene ring and the melting of the weak crystalline of polystyrene block, is observed from the MW2D correlation spectrum around 72-80oC. The glass transition temperature of polystyrene block is determined around 120oC. From MW2D correlation spectrum, we discover that, around 120oC, the chain segments movement of polystyrene block occurs before that of poly(ethylene-co-1-butene) block in phase interface. At 142oC, the fundamental chains of disperse phase (S block) center initiate to entirely move and this type of movements drive a fraction of disperse phase (S block) to deform from incomplete shape to sphere. It corresponds to the entirely viscous flow temperature of the fundamental chains of disperse phase.