Over　the　past　decade,　researchers　have　demonstrated　much　interest　in　laser　cladded　metal　matrix　composite　coatings　for　its　good　wear　resistance,　corrosion　resistance　and　high　temperature　properties.　The　effects　of　RE　on　the　microstructure　and　properties　of　laser　coatings　have　also　got　more　and　more　attention.　In　this　paper,　in　situ　Fe-NbC　composite　coatings　with　different　CeO2　addition　were　produced　on　die　steel　by　laser　cladding.　The　formation　mechanism　of　NbC　particles　was　analyzed.　The　effects　of　RE　on　microstructure　and　micro-hardness　of　coatings　were　investigated.　It　was　revealed　that　larger　NbC　particles　with　hard　edges　formed　around　Nb　particles,　and　smaller　flocculent　NbC　particles　formed　by　the　chemical　reaction　of　Nb　and　solid　graphite　in　the　molten　pool.　CeO2　plays　important　roles　in　reducing　micro-porosities,　refining　grains,　and　improving　the　precipitation　of　NbC.　Therefore,　the　average　micro-hardness　and　its　smoothness　from　the　top　to　the　bottom　of　the　coating　were　improved　after　adding　CeO2.　(C)　2013　Elsevier　B.V.　All　rights　reserved.