In this thesis, diamond-like carbon films (DLC) and related materials were deposited by an electrochemical method, and their compositions and structures were studied.(1) Deposition of Diamond-like Carbon Films by Electrolysis of Acetonitrile at a High Voltage.Diamond-like carbon films were deposited on Si substrate by electrolysis of acetonitrile at 60 癈 and 1600 V. The fact that current density fluctuates like the wave had been found. The surface morphology of the film was investigated by atomic force microscopy and transmission electron microscopy, and the results showed that the film was composed of small grains about 100 run in size. The results of Fourier transform infrared spectroscopy, Raman spectroscopy and X-ray photoelectron spectroscopy indicated that the films were typical hydrogenated DLC films the percentage of sp3-C is 30-35%.(2) Facile Deposition of Diamond-like Carbon Films by Electrolysis of Dimethylsulfoxide at a Low voltage.Diamond-like carbon films were deposited on Al and Si substrate, respectively, by electrolysis of dimethylsulfoxide at 75 ℃ and 150 V. The composition and structure of the films were characterized by X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy and Raman spectroscopy. The results showed that the deposits were typical hydrogenated DLC films. Atomic force microscopy and Scan electron microscopy were used to investigate the surface morphology of the sample, indicating that the films were composed of small grains about 100 nm in size. A possible growth mechanism of DLC films is proposed based on the structure and physical properties of dimethylsulfoxide.(3) Deposition of Doped Diamond-like Carbon Films by a Liquid-phaseElectrochemical RouteCopper-doped diamond-like carbon (Cu-DLC) films have been deposited on Si substrate by an electrochemical route from the acetonitrile solution of [Cu(CH3CN)4]ClO4 at 60@ and 1600 V. The results of Fourier transform infrared spectroscopy, Raman spectroscopy and X-ray photoelectron spectroscopy showed that the films were copper / hydrogenated amorphous carbon (Cu /a-C:H) with considerable sp3 carbon atoms, indicating that the addition of copper promoted the formation of sp3 carbon atoms. Transmission electron microscopy images showed that copper nanoparticles was atomically dispersed within the amorphous carbon matrix in the nanocomposite films. Fluorinated amorphous carbon films were also deposited on Si substrate by electrolysis of trifluoroacetic acid. Raman spectroscopy and X-ray photoelectron spectroscopy were used to investigate the composition and structure of the films.