Carbon nitride films were grown electrochemically through the application of a bias voltage to Si substrates immersed in acrylonitrile liquid. Continuous and uniform films were grown by the application of both negative and positive bias voltages. X-ray photoelectron spectra (XPS) of the grown films were studied to clarify their composition and bonding configurations. The XPS spectra show the presence of C, N, and O atoms as major components in the grown films. The atomic ratios of nitrogen to carbon in the films are estimated as 0.16 -0.28, which are comparable to those in amorphous carbon nitride (a-CN x ) films grown by conventional vapor deposition techniques. The analysis of C 1s and N 1s spectra reveals that the major bonding states of the grown films are attributed to a mixture of CN and hydrogenated C=N bonds.