A　dense　Cu-10Sn　alloy　bulk　specimen　was　obtained　by　optimizing　the　laser　powder　bed　fusion　(L-PBF)　processing,　and　the　relative　density　of　the　specimen　reached　99.7%.　The　grain　morphology　was　mainly　the　columnar　dendrite　and　inter-dendritic　phases　generated　along　the　solidification　direction.　Tensile　testing　and　detailed　microstructural　characterization　were　carried　out　on　specimens　in　the　as-built　and　heat-treated　condition.　Under　the　quasi-static　tensile　condition,　the　yield　strength　(sigma(0.2)),　ultimate　tensile　strength　(UTS),　and　the　elongation　of　the　as-built　Cu-10Sn　specimen　were　392　MPa,　749　MPa　and　29%,　respectively.　After　the　solution　treatment　at　800　degrees　C　for　4　h,　and　aging　treatment　at　400　degrees　C　for　2　hours,　the　microstructure　of　the　specimen　transformed　from　the　columnar　grain　to　equiaxed　grain,　the　dislocation　density　decrease,　and　numerous　annealing　twins　were　observed　in　the　heat-treated　state.　Therefore,　the　quasi-static　tensile　yield　strength　(sigma(0.2))　of　the　specimen　was　reduced　to　245　MPa.　However,　the　UTS　and　the　elongation　were　increased　to　840　MPa　and　56%,　respectively,　due　to　the　interaction　between　annealing　twins　and　equiaxed　grain.