Experimental　measurements　in　a　T-junction　with　one　inlet　and　two　outlets　mimicking　the　airflow　in　a　high-speed　train　ventilation　system　were　carried　out　using　well-resolved　Hot-Wire　Anemometry　(HWA).　Continuous　wavelet　transform　(CWT)　is　used　to　analyze　the　time-frequency　contents　of　the　instantaneous　streamwise　velocity;　and　the　discrete　wavelet　transform　(DWT)　is　employed　to　determine　the　multi-resolution　energy　characteristics.　The　measurements　and　analysis　are　carried　out　at　three　representative　streamwise　locations,　i.e.,　upstream,　mid-center,　and　downstream　of　the　T-junction.　The　results　show　that　the　normalized　time-average　velocity　at　the　mid-center　of　the　T-junction　is　the　largest　near　the　wall　region.　Comparing　the　CWT　data　in　the　region　near　the　wall,　it　is　found　that　the　dominant　frequency　of　the　periodic　high　energy　coherent　structures　increases　along　the　streamwise　direction,　and　the　wavelet　energy　magnitude　at　mid-center　of　T-junction　decreases　with　the　increase　of　velocity　ratio.　The　DWT　results　show　that　apparent　wavelet　energy　peak　appears　at　the　upstream　and　downstream　of　the　T-junction　for　different　scales　from　26　to　210,　but　not　at　the　mid-center.　However,　the　energy　at　scale　211　abruptly　rises　in　all　flow　regions　at　all　the　three　streamwise　locations　and　this　energy　decreases　with　the　increase　of　the　velocity　ratio.　Therefore,　a　higher　velocity　ratio　is　preferred　for　suppressing　the　generation　of　large-scale　coherent　structures　to　reduce　drag　forces　and　skin　frictions　for　high-speed　trains.　©　2018