SiNx-SiOy and SiNx-SiCy composite films have been deposited by a multisource plasma chemical vapor deposition (p-CVD) method. Two plasma generators are implemented to form the precursors of the respective component of the composite films. In each plasma generator, two kinds of source gas are fed into the generator and decomposed by two rf electrodes, respectively. The pressure of the reaction zone of the plasma generator is raised by throttling of the aperture of the plasma generator. With the p-CVD system, SiNx-SiOy and SiNx-SiCy composite films in which clusters of SiOy and SICy are distributed in the matrix of SiNx were deposited effectively, and then nodules were formed.