The　energy　separation　performance　of　the　vortex　tube　with　various　gases,　such　as　air,　nitrogen,　argon　and　carbon　dioxide,　was　studied　in　the　experiment,　whereby　cold　and　hot　characteristic　curves,　refrigeration　output,　unit　refrigeration　output　and　coefficient　of　performance　(COP)　versus　cold　flow　rate　were　obtained.　The　results　indicate　that　cold　and　hot　effects　are　closely　related　to　mol　mass:　the　bigger　the　mol　mass,　the　better　the　cold　and　hot　performance　will　be;　additionally,　these　effects　are　subjected　to　the　coefficient　of　Joule-Thomson　to　some　extent.　Refrigeration　output　and　COP　also　have　a　corresponding　direct　correlation　with　mol　mass,　in　addition　to　refrigeration　effect　and　specific　heat　at　constant　pressure.