In　this　paper　we　compared　the　two　methods　of　cell　sorting　(magnetic　cell　sorting　and　flow　cytometry　sorting)　for　the　isolation　and　function　analysis　of　mouse　CD4(+)　CD25(+)　regulatory　T　(Treg)　cells,　in　order　to　inform　further　studies　in　Treg　cell　function.　We　separately　used　magnetic　cell　sorting　and　flow　cytometry　sorting　to　identify　CD4(+)　CD25(+)　Treg　cells.　After　magnetic　cell　separation,　we　further　used　flow　cytometry　to　analyze　the　purity　of　CD4(+)　CD25(+)　Treg　cells,　trypan　blue　staining　to　detect　cell　viability,　and　propidium　iodide　(PI)　staining　to　assess　the　cell　viability.　We　detected　the　immune　inhibition　of　CD4(+)　CD25(+)　Treg　cells　in　the　in　vitro　proliferation　experiments.　The　results　showed　that　compared　to　flow　cytometry　sorting,　magnetic　cell　sorting　took　more　time　and　effort,　but　fewer　live　cells　were　obtained　than　with　flow　cytometry　sorting.　The　CD4(+)　CD25(+)　Treg　cells,　however,　obtained　with　both　methods　have　similar　immunosuppressive　capacities.　The　result　suggests　that　both　methods　can　be　used　in　isolating　CD4(+)　CD25(+)　Treg　cells,　and　one　can　select　the　best　method　according　to　specific　needs　and　availability　of　the　methodologies.