Epitaxial Ba0.6Sr0.4TiO3 （BST） thin films were deposited on LaAlO3 （LAO） substrates with the conductive metallic oxide La0.5Sr0.5CoO3 （LSCO） film as a bottom electrode by pulsed laser deposition （PLD）. X-ray diffraction θ~2θ and Ф scan showed that the epitaxial relationship of BST /LSCO /LAO was [001] BST// [001] LSCO//[001] LAO. The atomic force microscope （AFM） revealed a smooth and crack-free surface of BST films on LSCO-coated LAO substrate with the average grain size of 120 nm and the RMS of 1.564 nm for BST films. Pt/BST/LSCO capacitor was fabricated to perform Capacitance-Voltage measurement indicating good insulating characteristics. For epitaxial BST film, the dielectric constant and dielectric loss were determined as 471 and 0.03, respectively. The tunabilty was 79.59% and the leakage current was 2.63×10-7 A/cm2 under an applied filed of 200 kV/cm. Furthermore, it was found that epitaxial BST （60/40） films demonstrate well-behaved ferroelectric properties with the remnate polarization of 6.085 μC/cm2 and the coercive field of 72 kV/cm. The different electric properties from bulk BST （60/40） materials with intrinsic paraelectric characteristic are attributed to the interface effects.
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