Si-C-N nanocomposite films on titanium substrate were prepared by arc enhanced magnetron sputtering (AEMS). The microstructure and properties of Si-C-N nanocomposite films were investigated. The results show that a nanocomposite of amorphous C–C, C=C, N–C and Si–C matrix is formed for the films. The microhardness of the films is (38.2±4.1) GPa. The fracture toughness of the films is (3.68±0.32) MPa·m1/2. Si-C-N nanocomposite films have a low friction coefficient of 0.23 at room temperature. The corrosion rate of TA2 with Si-C-N nanocomposite films is 0.000 125 mm·a-1 in 3.5%NaCl water solution at 25 oC, which is 12.5% of that of pure TA2 under the same condition. The TA2 with Si-C-N nanocomposite films has better wear resistance and corrosion resistance than pure TA2.