Abstract: In order to study the effect of high distribution density droplets on the mechanical properties of ta-C film and substrate temperature on the distribution density of droplets, direct current vacuum cathodic arc（DCVA） and filtered vacuum cathodic arc（FCVA） were used to prepare ta-C films with different droplets distribution density under different substrate temperatures. The surface morphology, roughness, microstructure, nanohardness and tribological properties of ta-C films were characterized by scanning electron microscopy, 3D optical profilometer, Raman spectroscopy, X-ray photoelectron spectroscopy, nanoindenter and ball-on-disk tribometer respectively. The sp3C content of ta-C films prepared by DCVA and FCVA is similar while does not heat the substrate. The results show that the high distribution density of droplets reduces the friction coefficient, wear rate and hardness of ta-C films. The increase of substrate temperature has no significant influence on the distribution density of ta-C films prepared by DCVA, but reduces the friction coefficient of that, while the wear rate of that keeps lower than that of the films prepared by FCVA.