Amorphous carbon nitride films were prepared at various substrate bias voltage Vh using magnetic filtered plasma stream. The plasma stream was formed by sputtering a high-purity graphite target in nitrogen atmosphere. The incident ions energy was varied by applying different negative bias voltage on the substrate platform. The atomic bond structure and chemical states of C and N atoms in the films as a function of bias voltage were studied by Raman spectra, FTIR spectra and atomic force microscopy (AFM). The results show that amorphous carbon nitride films with larger sp(3) C-N bond and sp(2) C-N bond can be formed in a Vh range from -60 to -120 V. The effect of incident ions energy on atomic bond structure and surface roughness of carbon nitride films was discussed.