Polyvinylpyrrolidone (PVP) and polyvinyl alcohol (PVA) polymer blend composite films doped with lanthanum (La) and chromium (Cr) ion were prepared via solution casting method. The x-ray diffraction (XRD) technique was used to examine the structural characteristics. UV-Visible photospectroscope was employed to measure optical properties and dielectric properties was measured using LCR meter. XRD results showed the semicrystalline behaviour of prepared films. Cr ion doped polymer blend composite film had an optical band gap of 4.17 eV, whereas La ion doped films had a band gap of 4.769 eV. From the comparative study of the (PVP:PVA)-Cr3+ and (PVP:PVA)-La3+ composite polymer films it was observed that La3+ doped film had lower dielectric constant. The ac conductivity of the (PVP:PVA)-Cr3+ film is found to be higher than the (PVP:PVA)-La3+ film.