The series of ethylene oxide-ethylene terephthalate segmented copolymers(EOET) with different long soft segments and different hard segment contents were synthesized. The crystallinity and morphology of EOET segmented copolymers were studied by using DSC and polarizing microscopy methods. Only when PEO molecular weight isn′t lower than 4000, are the PEO segments able to crystallize at usual processing conditions. The crystallinity of PEO segments is influenced by hard segments contents and its crystallinity. The formation of hard segment domains is easy in EOET segmented copolymer. The hard segment domains act as physical crosslinks at temperatures above the melting point of the PEO crystals. The structural characteristics of EOET segmented copolymer may exhibit shape memory effect.