By　means　of　a　single-tube　set-up,　the　effect　of　jet　flow　exciting　frequency　(f)　on　refrigeration　efficiency　(η)　and　the　influence　of　some　factors,　i.e.　tube　length,　expansion　rate,　heat　transfer　conditions　and　discharging　at　the　heat　end　of　the　tube,　on　optimal　jet　flow　exciting　frequency　are　studied　experimentally.　The　results　show　that　there　exists　a　number　of　peak　value　refrigeration　efficiency　when　the　exciting　frequency　is　increased.　The　variation　of　η　due　to　the　change　of　f　can　be　over　12%.　The　optimal　jet　flow　exciting　frequency　is　significantly　decreased　when　the　tube　length　is　increased,　the　expansion　rate　is　decreased,　the　heat　transfer　condition　outside　of　the　tube　is　improved,　or　a　part　of　heat　gas　is　discharged　at　the　heat　end　of　the　tube.　An　optimal　parameters　matching　relationship,　which　can　be　used　to　predict　the　value　of　the　optimal　jet　flow　exciting　frequency,　is　obtained.