Pendent groups’ functionalization of polyimide is an optimum approach to improve its processability and achieve functionalized polyimide materials. There are two types of modification routes for pendent groups’ functionalization of polyimide: monomer route and macromolecular route. In this paper, various approaches for pendent groups’ functionalization of polyimide are introduced. At the same time, a new method to achieve functional polyimide materials without decreasing its thermal stability and mechanical properties is mentioned. There are two types of modification routes for pendent groups’ functionalization of polyimide: monomer route and macromolecular route. In this paper, various approaches for pendent groups ’functionalization of polyimide are introduced. At the same time, a new method to achieve functional polyimide materials without decreasing its thermal stability and mechanical properties are mentioned.