Thin platinum layer of 100 Angstrom thickness was used for the modification of the interface state between (Ba,Sr)TiO3 (BST) thin films and RuO2 bottom electrodes. Pt/RuO2 hybrid bottom electrodes were fabricated with various platinum deposition temperatures by a conventional de magnetron sputtering method. Although the surface morphology and X-ray diffraction (XRD) patterns of BST thin films were not changed, the electrical properties of BST films deposited on Pt/RuO2 hybrid electrodes were improved compared to the films on RuO2 electrodes. Dielectric constant (epsilon(r)) and leakage current density of the 1000 Angstrom thick BST thin films on Pt/RuO2 hybrid electrodes prepared at the platinum deposition temperature of 400 degrees C were 498 and 8.6 x 10(-8) A/cm(2) at 1.5 V, respectively.