Smoothing, dense and uniform nano-crystalline diamondlike carbon films are pr epared by using electron cyclotron resonance (ECR) microwave acetone plasma chemical vapor deposition (CVD) method. Atomic force microscope shows that, the surface roughness of this film is less than 10nm, the average grain size is abou t 100nm, and there are no distinct Raman shift peaks. Middle infrared spectra sh ow the existence of sp1, sp2, and sp3 mixed C—C bond, sp3 mixed CH3,CO, COOH and other oxygenic hydrocarbons in the film. The micr ohardness is about 4GPa, bulk elastic modulus is about 11 GPa tested by nano-indentation. Without absorption in closed infrared area, the refractive index is 1.576 and the calculated deposition rate is 460 nm/h for the film.