A transparent nano-composite TiO2-PI was prepared by properly controlling the sol-gel reaction, imidization and polymerization process. The paper summarized the factors that may influence the TiO2-PI nano-composite morphology. The microstructure of the nano-composite depends strongly on the composition and synthesizing route, Fr-IR, DSC, XRD and UV-Vis analysis were carried out to observe the specific thermal, optical properties and the microstructure. The relationship between them was also suggested. (C) 2002 Elsevier Science B.V. All rights reserved.