This　study　establishes　the　primary　culture　method　for　red　carp　(Cyprinus　carpio)　macrophages　in　vitro　and　lays　the　foundation　for　further　research　in　the　fish　immune　system.　The　healthy　adult　red　carp　was　chosen,　and　mechanical　separation　and　cell　adherent　culture　methods　were　used　to　isolate　the　primary　macrophages.　Compared　to　the　traditional　method　of　Percoll　discontinuous　density　gradient　isolation,　the　protocol　we　reported　here　makes　cell　isolation　steps　more　concise　and　obtains　more　healthy　cells　with　high　macrophage　purity.　The　cells　were　uniform　in　size　with　a　clearly　visible　nucleus.　Trypan　blue　staining　and　non-radioactive　cell　proliferation　assay　were　used　to　detect　the　cell　survival　rate.　Further,　we　provide　optimum　culture　conditions　which　include　cell　density　(1　x　10(7)　cells/mL),　culture　medium　(Leibovitz＇s　L-15),　pH　(7.2-7.4),　temperature　(26A　degrees　C),　and　adherent　time　(24　h).　Macrophages　have　been　identified　by　nonspecific　esterase　and　Wright-Giemsa　staining　and　have　shown　to　grow　very　well.　In　addition,　the　macrophages　have　a　very　strong　bactericidal　activity　against　three　kinds　of　bacteria,　further　verifying　good　growth　conditions　and　proper　function.