The work aims to compare friction and wear behavior of TiN and TiSiN coatings sliding against Al2O3 in seawater. TiN and TiSiN coatings were fabricated on 316L stainless steel and monocrystalline silicon wafer by adopting cathodic arc ion plating technique. Cross-sectional morphology and chemical composition of the coatings were analyzed with SEM, XRD and XPS. Hardness and elasticity modulus of the TiN and TiSiN coatings were measured with nano-indentor. The friction and wear behavior of TiN and TiSiN coatings sliding against Al2O3 in simulated seawater was studied with UMT-3 reciprocating friction testing machine. Friction and wear conditions of grinding cracks were thoroughly analyzed with SEM, EDS and a surface profiler. Hardness of TiN coating was 32.5 GPa. After silicon was doped, hardness of the TiSiN coating was up to 37 GPa. Meanwhile, , corrosion current density of TiSiN coating decreased by one order of magnitude compared to TiN coating. In the frictional experiment, friction coefficient and wear rate of the TiN coating was 0.35 and 5.21×10-6 mm3/(N?m), respectively. In contrast, friction coefficient and wear rate of the TiSiN coating decreased significantly to 0.24 and 1.96×10-6 mm3/(N?m), respectively. Tribological properties of the TiN coating are obviously improved by silicon doping due to dense structure, improvement of hardness, toughness and corrosion resistance, and formation of lubrication phase.