This　study　investigated　the　anisotropic　characteristics　of　the　microstructural,　mechanical　and　corrosion　properties　of　CoCrFeMnNi　high-entropy　alloy　produced　by　selective　laser　melting　(SLM)　additive　manufacturing　(AM).　Under　the　extremely　high　thermal　gradient　during　the　SLM　process,　a　columnar　solidification　structure　with　a　single　face-centered　cubic　(FCC)　phase　structure　was　formed.　The　crystal　structure　exhibited　a　regular　checkerboard　structure　in　the　XOY　plane　(perpendicular　to　the　building　direction),　which　was　composed　of　{110}　direction　and　a　small　amount　of　{100}　fiber　texture.　The　cellular-dendritic　sub-structures　formed　in　the　columnar　crystal　structure　with　sizes　of　about　500　nm　in　diameter.　As　for　the　mechanical　properties,　the　XOY　plane　exhibited　higher　ultimate　tensile　strength　and　yield　strength　(σ0.2)　but　lower　elongation　to　failure　compared　to　the　XOZ　plane　(parallel　to　building　direction),　which　reflected　the　anisotropy　of　the　microstructure.　The　electrochemical　test　results　of　the　different　planes　showed　that　the　XOZ　plane　exhibited　better　corrosion　resistance　in　comparison　with　the　XOY　plane　in　the　3.5　wt　%　NaCl　solution,　which　was　on　account　of　the　selective　attack　at　the　Mn-rich　inter-cellular　regions　and　the　different　structures　of　the　cellular-dendritic　sub-structures　on　different　planes.