ε-caprolactone〖DK〗）〖DK〗（PCL）/polylactide（PLA）blend was prepared by melt mixing and its morphology and structural rheology were studied by using scanning electron microscope（SEM）and coneplate rheometerThe results showed that the PCL/PLA blend presented a typical immiscible phase structure，which was dependent on the mass ratio between two components stronglyWith increasing PCL component loading level，the morphology of dispersed spherical droplets in the continuous phase changed into fibrous and finally to the cocontinuous structureThe presence of the phase interface led to remarkable increase of the dynamic elastic response of the blend，and also to the appearance of dynamic shape relaxationHowever，the dependence of modulus on the frequency can only be used to estimate the presence of the immiscible interface，and the detailed differences among those immiscible phase structures should be characterized by relaxation curves.