Microstructures,　Surface　morphology　and　composition　of　nanocrystalline　Ni-Co　alloy　coating　and　Ni-Co/SiC　nanocomposite　coating　synthesised　by　pulse　electrodeposition　have　been　studied　by　XRD,　SEM　and　EDS.　The　corrosion　characteristics　of　nanocrystalline　Ni-Co　alloy　coating　and　Ni-Co/SiC　nanocomposite　coating　were　comparatively　investigated　by　immersion　corrosion　test　and　electrochemical　polarisation　method　respectively.　The　experimental　results　indicate　that　nanocrystalline　Ni-Co　alloy　coatings　and　Ni-Co/SiC　nanocomposite　coatings　can　be　synthesised　by　pulse　electrodeposition.　With　introducing　and　increasing　nano-SiC　particles,　the　grain　size　of　Ni-Co/SiC　nanocomposite　is　being　decreased　while　the　microhardness　is　increasing.　The　Ni-Co/SiC　nanocomposite　coating　exhibited　better　corrosion　resistance　in　3·5　wt-%　NaCl　solution　and　5　wt-%　HCl　solution　than　nanocrystalline　Ni-Co　alloy.　The　surface　morphology　of　all　samples　after　corrosion　in　3·5　wt-%　NaCl　solution　show　evidences　of　little　corrosion.　However,　samples　corroded　in　5　wt-%　HCl　solution　show　uniform　corrosion.　©　2011　Institute　of　Materials,　Minerals　and　Mining.