New WC-CrAlN superlattice films have been deposited on Si(100) substrate using a cathodic arc ion plating system. A substrate holder was rotated with a range from I to 12 rev./min to control the thickness of layered structures, and on arc power density of Al cathodes was controlled to change the Al concentration in the film. The microstructure and mechanical properties of the film depend on the superlattice period (lambda) and Al concentration. The chemical composition was evaluated by glow discharge optical emission spectroscopy (GDOES). Using X-ray diffraction analysis (XRD), it is observed that the preferred orientation of microstructure is changed according to the superlattice periods (lambda) and Al concentration. Through transmission electron microscope (TEM) analysis, the microstructure and superlattice period (lambda) of the WC-CrAlN superlattice film were confirmed. The hardness of the deposited film was evaluated by a nanoindentation test. As a result of the nanoindentation test, the hardness of WC-CrAlN superlattice film gained approximately 40 GPa at the superlattice period (lambda) of 7 nm. The structure of WC-CrAlN superlattice film was transformed from dense columnar structure to a nanocomposite structure.