The preparation and characterization of composite polymer electrolytes (CPE) of Polyindole-Fe 2 O 3 -LiClO 4 for different concentrations of indole have been reported. Formation of polyindole -Fe 2 O 3 composite was confirmed by FTIR and XRD. The surface morphology of the composite was studied by SEM. Its microstructure and chemical analyses were performed by transmission electron microscopy and electron energy loss spectroscopy respectively. Ionic conductivity of CPE analyzed by impedance spectroscopy was found to depend on the indole concentration. This type of CPE system can be used as a solid electrolyte in lithium ion polymer batteries.