The　microstructures,　surface　morphology　and　composition　of　nanocrystalline　Ni-Co　alloy　and　nano　SiC/Ni-Co　composite　coating　prepared　by　pulse　electrodeposition　were　studied　by　XRD,　SEM　and　EDS.　The　corrosion　characteristics　of　nanocrystalline　Ni-Co　alloy　and　nano　SiC/Ni-Co　composite　coating　were　comparatively　tested　by　the　soak　method　and　the　electrochemical　polarization　method,　respectively.　The　experimental　results　indicate　that　typical　nanocrystalline　Ni-Co　alloy　and　nano　SiC/Ni-Co　composite　coatings　can　be　synthesized　by　pulse　electrodeposition,　and　with　the　increasing　of　the　nano　SiC　particles,　the　grain　size　of　nano　SiC/Ni-Co　composite　coating　is　diminished　while　the　microhardness　is　increased.　The　nano　SiC/Ni-Co　composite　coating　has　better　dispersion　and　it　exhibits　better　corrosion　resistance　in　3.5　wt%NaCl　and　5　wt%HCl　solution　than　the　nanocrystalline　Ni-Co　alloy.　The　surface　morphology　of　all　samples　after　corrosion　in　3.5　wt%NaCl　solution　shows　good　corrosion　resistance,　while　the　samples　show　spot　corrosion　in　5　wt%HCl　solution.