Metallic　elemental　powder　mixture　and　pre-alloyed　metallic　powder　are　both　frequently　used　powder　feedstock　in　the　additive　manufacturing　process.　However,　little　research　has　been　conducted　to　compare　the　corrosion　behavior　of　selective　laser　melting　(SLM)　alloys,　fabricated　by　pre-alloyed　metallic　powder　and　mixed　metallic　powder.　Hence,　it　is　important　to　investigate　the　corrosion　behavior　of　SLMed　alloys,　as　well　as　the　corresponding　cast　ingot,　with　the　aim　to　better　understand　the　feasibility　of　designing　new　materials.　In　this　work,　the　SLM-produced　Ti6Al4V3Cu　alloys　were　manufactured　using　a　metallic　elemental　powder　mixture　and　pre-alloyed　metallic　powder,　respectively.　The　corrosion　behavior　of　the　different　Ti6Al4V3Cu　alloys　was　investigated　in　following　electrochemical　tests　and　ion　release　measurements.　The　results　showed　that　the　Ti6Al4V3Cu　alloy　prepared　by　pre-alloyed　metallic　powder　showed　better　corrosion　resistance　than　that　produced　from　mixed　metallic　powder.　Moreover,　the　SLM-produced　Ti6Al4V3Cu　alloys　performed　significantly　better　in　corrosion　resistance　than　the　cast　Ti6Al4V3Cu.　The　results　are　expected　to　achieve　a　better　understanding　of　the　feasibility　of　designing　new　materials　using　mixed　powders,　contributing　to　reducing　development　costs　and　cycles.