Laser　melting　deposition　(LMD)　technology　is　characterized　by　a　fast-forming　speed,　additive　manufacturing,　and　a　multi-axis　operating　system,　which　is　suitable　for　preparing　hard　alloy　parts　with　complex　structures.　This　study　mainly　focused　on　analyzing　the　microstructure　and　mechanical　properties　of　cemented　carbides　fabricated　via　LMD　on　different　substrates.　The　results　showed　that　the　cemented　carbide　formed　on　the　WC-20Co　cemented　carbide　substrate　had　a　higher　density　and　fewer　cracks　and　pores　compared　with　fabricating　on　the　45#　steel　substrate　because　the　composition　of　the　substrate　and　powder　had　similar　thermal　expansion　coefficients,　and　so　the　deposition　effect　was　better.　The　smaller　grain　size　in　the　microstructure　of　the　cemented　carbide　formed　on　a　45#　steel　substrate　was　possibly　influenced　by　the　difference　of　liquid　phase　point　and　the　solid　solubility　between　45#　steel　and　WC-20Co　cemented　carbide.　Firstly,　45#　steel　has　the　higher　liquid　phase　point　(1495　degrees　C)　compared　with　WC-20Co　(1320　degrees　C),　which　made　less　liquid　phase　produced　during　SLM　processing.　Meanwhile,　the　solid　solubility　of　WC　in　45#　steel　(7　wt%)　is　lower　than　in　Co　(22　wt%),　the　dissolution　process　of　WC　grains　was　limited,　thus,　the　growth　of　WC　grains　was　hindered.　Compared　with　the　samples　prepared　on　the　45#　steel,　the　hardness　was　higher　for　the　alloys　fabricated　on　cemented　carbide　substrate,　which　was　mainly　due　to　the　higher　density　of　the　samples　and　the　higher　eta-phase.