The (AlCrTaTiZr)Cx films are deposited onto Si substrates and cemented carbide plates by dual-gun RF magnetron sputtering. The carbon contents are controlled by tuning the applied power of each target, and ranged from 0 to nearly 50 at.% determined by EPMA analysis. The influence on the crystal structure, cross-sectional microstructure, hardness and other mechanical properties is also investigated. Without the carbon additions, the AlCrTaTiZr alloy film exhibits an amorphous structure and shows a glass-like microstructure by SEM observation. Another distinguished peak in XRD pattern is found as the carbon atoms are incorporated, which is considered as the multi-element carbide phase. These (AlCrTaTiZr)Cx films perform a nanocomposite structure with FCC carbide nanocrystallites embedded in an amorphous alloy matrix. The hardness and modulus are increasing with the raised carbon contents. The friction coefficient and wear rate of coatings are also improved by carbon addition.