Water　is　a　kind　of　natural　refrigerant,　which　is　environmentally-friendly,　safe　and　cheap.　Water　vapor　compression　refrigeration　system　is　another　form　using　it　as　the　refrigerant.　In　the　cyclic　process,　the　whole　system　is　under　negative　pressure.　To　further　study　the　effect　of　surfactants　on　evaporator　heat　transfer　in　the　system,　this　paper　focuses　on　experimental　study　on　properties　of　2-ethylhexanol　aqueous　solution.　Through　measuring　the　surface　tension　and　the　contact　angle　on　copper　plat,　the　critical　micelle　concentration(CMC)　of　2-ethylhexanol　aqueous　solution　is　found　to　be　1000mg.L-1　at　25　degrees　C,　that　is,　the　optimal　concentration　to　enhance　heat　transfer　is　1000mg.L-1.　The　relations　between　surface　tension　and　concentration　are　built,　which　provide　the　experimental　basis　for　the　study　that　solution　concentration　changes　effect　on　the　heat　transfer　of　evaporator　in　water　vapor　compression　refrigeration　system.