We report on the preparation and characterization of RuO2 thin films by metal-organic chemical vapor deposition (MOCVD) method and reactive sputtering under various conditions. The Auger electron spectroscopy depth profile shows good compositional uniformity across the thickness of the films. As confirmed by X-ray investigations, the films crystallize with the correct rutile structure. The results of the electrical and optical studies of the films show a metallic character of the films deposited at substrate temperature higher than 100 degrees C. The grain-boundary scattering model fits well for the films with an average grain size of about 12-50 nm. The red shift and broadening of the line width of the Raman peaks are analyzed by the spatial correlation model. The results of Raman investigation indicate that a nearly strain free and high-quality RuO2 thin film could be deposited on a Si substrate.