The transesterification in polycarbonate/poly(ethylene-co-acrylic acid)(PC/EAA) melting blend system with the presence of dibutyltin oxide (DBTO) catalyst was investigated during compounding by means of a Haake torque rheometer．The characteristics of the products were evaluated by Soxhlet extraetion and DSC．1H-NMR analyses．The results showed that the transesterification reaction did take place in the PC/EAA blend svstem．grafted or co-crosslinked copolymers PC

EAA were in situ generated at the interface of the blends during processing；the extent of exchange reaction

the structure and stability of reaction products depended upon the mixing time and the content of the catalyst．With mole catalyst and reaction time

more co-crosslinked copolymers were obtained.