Thin films of ferroelectric Pb0.82La0.82Sr0.1Ti0.98O3 (PLST) thin films were fabricated on LaNiO3 buffered Pt/Ti/SiO2/Si substrates via the sol-gel deposition method. The dielectric and tunable properties were investigated as a function of DC bias and frequency to exhibit effect of LNO buffer layer on the tunable dielectric thin film. It shows that PLST thin film deposited on LNO/Pt/Ti/SiO2/Si substrates possesses higher dielectric constant and lower dielectric loss compared with the one directly deposited on Pt/Ti/SiO2/Si substrates. Furthermore, the tunability of the LNO-buffered PLST thin film is 68% at the DC bias of 20 V, which is higher than 60% of the pure PLST thin film. The results suggest the addition of LNO buffer layer could effectively improve the dielectric and tunable properties of PLST thin film and make it suitable for high quality dielectric tunable devices. (C) 2014 Published by Elsevier B.V.