The maleic anhydride grafted polypropylene （PP-g-MAH） was used as a compatibilizer to improve the immiscible phase morphology of polypropylene/poly(ethylere terephthalate)(PP/PET) blends.The effect of PP-g-MAH on the phase morphology and structural rheology of the blends was studied.The results show that for PP/PET blends with PET-rich composition

the addition of PP-g-MAH reduces the dispersed PP particle size remarkably

leading to large change in the shape relaxation and deformation as well as break-up behavior of PP drops.For PP/PET blends with the components around the phase inversion point

the coexistence of phase morphology of `sea-island' and cocontinuous structure disappears with addition of PP-g-MAH.The enhancement in dependency of low-frequency modulus on frequency also indicates that phase interactions increase due to the compatible effect.However

for PP/PET blends with rich PP component

the addition of PP-g-MAH nearly has no influence on both the morphology and rheology.