A new electrodeposition system, with a thin nickel wire as the anode, was used to deposit the CN x thin film on Si(100) substrate from a dicyandiamide-saturated solution in acetonitrile at a high potential. During the experiment, when a certain high potential was applied, spark occurred between the Ni wire anode and the Si(100) substrate. The films were characterized by X-ray photoelectron spectroscopy(XPS), Fourier-transform infrared spectroscopy(FTIR), scaning electron microscopy(SEM) and X-ray diffraction(XRD). It was indicated that multiphase of α-C 3N 4, β-C 3N 4 and g-C 3N 4 was obtained in the films. This work is the first attempt to deposit carbon nitride material through a thin nickel wire anode and might provide a new route for preparing pure crystalline C 3N 4.