Thermal properties and morphologies for polymer blends of poly(ethylene terephthalate) (PET) and epoxidised natural rubber with 25 mole % (ENR-25) and 50 mole % epoxy content (ENR-50) were studied by using differential scanning calorimeter (DSC) and polarizing optical microscope (POM), respectively.The blends were prepared by precipitation method.Immiscibility of the components is revealed by observation of two glass transition temperatures (Tg) that correspond to that of the neat constituents.