An　experimental　study　has　been　conducted　for　the　transient　boiling　heat　transfer　of　a　hot　surface　on　the　condition　of　water　jet　impingement　quench　cooling.　The　complete　boiling　curves　on　different　subcooling　degrees　of　jet　fluid,　δTsub,　and　different　jet　velocity,　Vo,　have　been　obtained.　The　results　revealed　that　increasing　either　jet　velocity　or　subcooling　degree　always　promotes　the　hot　surface　cooling　rate.　With　constant　δT3Ub　and　Vo　the　surface　temperature　varies　by　fast-slow-fast　law.　The　critical　heat　flux　qc-　gets　higher　as　the　average　transition　rate　of　the　surface　temperature　dTw/dτ　increases.　The　relationship　between　the　two　variables　presents　linear　characteristic.