Abstract: The modification of aromatic polyimide such as blending and copolycondensation was introduced in this article. In terms of introducing different groups, copolymerization modification can be classified into polyamideimide, polyester imide, nitrogencontaining heterocyclic and so on. Structural modification includes the introduction of hybridized element, functional perdant group, scrolt structure and noncoplanar structure into main chain.The application of polyimide in the field of flame retardant was also discussed.

Key words: polyimide, flame retardancy, modification