A series of blends with different compositions were prepared by melt-mixing on the basis of polystyrene and poly(ethylene oxide). Using the relative energy dissipation method, the dynamic behavior of the blends above the glass transition temperature was investigated. Two relaxational dissipation peaks (α and α′) were observed. It is suggested that peak α is associated with the glass transition of polystyrene and peak α′ with the liquid-liquid transition. The relaxation time τ of both relaxations does not satisfy the Arrhenius law. The effect of composition on the dynamic relaxation of the blends were also discussed qualitatively.