An　experimental　study　is　performed　to　investigate　the　interfacial　characteristics　of　steam　jet　condensation　in　crossflow　of　water　in　a　vertical　pipe.　A　high-speed　camera　is　applied　to　capture　the　raw　images　of　the　condensing　jet　in　the　flow　visualization　test　section.　According　to　both　the　gray　and　gray-gradient　profiles　of　the　original　images,　an　interfacial　identification　method　is　proposed　to　reveal　the　interfacial　characteristics,　including　the　jet　plume　shape,　jet　centerline　trajectory　and　jet　penetration　length.　Based　on　the　expansion　features　of　the　two　phase　interface,　the　condensation　regimes　are　classified　into　five　categories,　including　double　expansion-contraction,　expansion-contraction,　cylinder,　contraction　and　hemisphere　shapes.　The　steam　mass　flux,　scaled　by　critical　steam　mass　flux　at　ambient　pressure,　is　found　to　be　irrelevant　to　the　transitional　lines　among　the　hemisphere,　conical　and　expansion-contraction　shapes　in　the　condensation　regime　map.　The　jet　momentum　ratio　as　a　dominant　factor　is　introduced　to　correlate　the　jet　centerline　trajectory,　and　the　predicted　results　are　within　20%　of　the　experimental　data.　The　dimensionless　jet　penetration　length　decreases　with　increase　of　ambient　pressure,　and　is　found　to　be　in　the　range　of　0.58-6.49　in　present　experiments.　A　correlation　for　prediction　of　the　dimensiOnless　jet　penetration　length　is　established,　and　the　discrepancies　between　the　predicted　results　and　experiments　are　within　+/-　15%.　(C)　2016　Elsevier　Ltd.　All　rights　reserved.