Diamond-like carbon (DLC) films were deposited on Si substrates by a dual direct current and radio frequency plasma-enhanced chemical vapor deposition (DC-RF-PECVD) technique. The effect of RF power on the surface morphology, micros tructure, hardness and Young's modulus of DLC films was investigated by atomic f orce microscopy, Raman spectroscopy, x-ray photoelectron spectrometry, infrared spectroscopy and nano-indentation. The films produced by DC-RF-PECVD have typical hydrogenated diamond-like characteristics, and the surface of the film s was smooth and compact.With the increase of RF power the bonded hydrogen conte nt in the films decreased while the sp33 content, hardness and Youn g's modulus of the DLC films reached the maxima at an RF power of 100W and then they decr eased with further increase of the RF power.