Polymer blending is a common and effective way to develop new materials with desirable physical and mechanical properties. Since most polymer pairs are immiscible, reactive compatibilization has been extensively studied to stabilize morphology of polymer blends and improve their mechanical properties. In the past several years, considerable interest has been expressed in understanding the fundamental kinetics and mechanisms of the interfacial reaction, investigating the reinforcement of the interfacial adhesion and the development of morphological structure at polymer-polymer interface induced by the interfacial reaction. The present review focused on some theoretical and experimental results that include the formation and growth of copolymers at the interface, and also the major factors such as reaction conditions, the concentration and bulk properties of the functionalized polymer, the thermodynamic interaction between the functionalized polymer and the matrix, which can influence the interfacial adhesion and morphological development. POLYM. ENG. SCI., 50:2273-2286, 2010. (C) 2010 Society of Plastics Engineers