Abstract: Microwave plasma chemical vapor deposition was applied to deposited diamond films in a CH₄/H₂/CO₂ system.The controllable growth of diamond films in a CH₄ rich system was achieved by varying the flow ratio of CO₂/CH₄. By using the Raman spectra，X-ray diffraction and SEM，the qualities，growth orientations and the surface morphologies were characterized.The results showed that only by changing the flow ratio of CO₂/CH₄ can significantly affected the surface morphologies and qualities of deposited diamond films and achieved the controllable growth of nano-scale，（111）-faceted and（100）-faceted diamond films.