Carbon cones are prepared on Si substrates film in plasma-enhanced hot filament chemical vapor deposition system using CH4, H2 and NH3 as the reaction gas, and the substrates are deposited with Ti and carbon film, respectively. Morphology and structure of the carbon cones are characterized by field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX)and micro-Raman spectroscopy. The SEM results indicate that the carbon cones are formed on the Si substrate deposited with carbon film. Furthermore, the EDX and Raman spectra indicate that the formed carbon cones are carbon nitride structure, which are composed of sp 3 C-N, sp 2 C and sp 2 C=N bonds. According to the mechanisms of sputtering and diffusion, the formation of carbon cones is analyzed. Simultaneously, the photoluminescence background in the Raman spectrum of carbon cones is analyzed, and results indicate that the carbon cone evolves from nonpolar carbon material to polarity carbon material due to the doping of nitrogen.