Five groups of diamond-like carbon (DLC) films with different arc currents were deposited on cemented carbide substrates by arc ion plating (AIP), aimed at the preparation of the super-hard ta-C film. The in?uences of arc current on the phase structure, microstructure, carbon atoms bond, mechanical properties and friction behavior of DLC ?lms were studied from various measurement tools, such as scanning electron microscope, Raman spectroscopy, X-ray photoelectron spectrometry, nanoindenter and ball-on-disk tribometer, respectively. The re-sults indicated that when the arc current is the lowest at 30 A, the surface of DLC film is the most smooth and compact, and the number of large particles in the least. The minimal ratio ID/IG and the maximum sp3 bond content are 0.87 and 64% at the arc current of 30 A, respectively. The ta-C film exhibits excellent performance including the highest hardness and modulus of 56.7 GPa and 721.1 GPa, the highest elastic recovery coefficient of 58.9% and the lowest friction coefficient is 0.073 while arc current is 30 A. However, the surface of the film becomes loose and porous, and the number of large particles on the surface increase with the increase of arc current. The ratio ID/IG increases and sp3 bond content decreases with increasing arc current. The hardness and modulus of DLC films decrease gradually, the ratio H/E changes little and H3/E2 decreases, and the friction co-efficient increases with increasing arc current. In summary, the results show that when the arc current is smaller, the ta-C film with super hard tetrahedral amorphous can be prepared by arc ion plating, and has excellent com-prehensive properties.