With the promise of its high conductivity, the ceramic Li1.3Al0.3Ti1.7(PO4)3 (x =0.85) of Li3−2x (Al1− x Ti x )2(PO4)3 (x =0.55 to 1.0), as a lithium fast ionic conductor, is produced by a conventional solid-state reaction and introduced into the poly(ethylene oxide) (PEO)-based composite polymer electrolyte films (CPE) to improve their ionic conductivity. The CPE films are prepared by a solution-cast technique and their characteristics are investigated by several experimental techniques including X-ray diffraction (XRD), infrared (IR) spectra, differential scanning calorimetry (DSC), and scanning electron microscopy (SEM). As measured by electrochemical impedance spectrum (EIS) measurement, the temperature-dependent ionic conductivity of PEO–Li1.3Al0.3Ti1.7(PO4)3 film with EO/Li=16 is maximized at 2.631×10−6 Scm−1 at room temperature and at 1.185×10−4 Scm−1 at 343K, while the ionic conductivity of the PEO–LiClO4–Li1.3Al0.3Ti1.7(PO4)3 film with EO/Li=8 is maximized at 7.985×10−6 Scm−1 at room temperature and at 1.161×10−3 Scm−1 at 373K when Li1.3Al0.3Ti1.7(PO4)3 content is 15wt.%.