The organic lithium salt, lithium p-[methoxy oligo(ethyleneoxy)] phenylsulfonate (EOnPSLi), possesses the ability of self-dissociation which leads to the exhibition of ionic conduction. The length of the ethyleneoxy repeating units in EOnPSLi has effects on the morphology, the self-dissociation ability, the ＇salt＇ concentration, the ionic conductive behaviour and the activation energy of ion transport of the oligoether salt, which consequently influences the ionic conductivity. In the complex of poly(ethylene oxide) (PEO) and EO2PSLi, with a decrease of EO2PSLi content the phase structure of PEO changes gradually from a dispersed island-like structure to a well-distributed, continuous structure. The corresponding ionic conductive behaviour changes from Arrhenius type to non-Arrhenius type in which the transport of ion carriers depends on the segmental movement of PEO macromolecules.