Micro/mini-channel　heat　sinks　are　extensively　utilized　in　heat　dissipation　systems　that　involve　high　heat　flux　components.　These　heat　sinks　are　preferred　due　to　their　compact　size　and　excellent　heat　transfer　efficiency.　The　selection　of　a　refrigerant　condensation　system　for　the　heat　dissipation　system　under　vapor　conditions　is　crucial.　In　order　to　investigate　the　heat　transfer　characteristics　of　flow　condensation　in　a　mini-channel,　a　visual　experiment　system　was　used　with　a　hydraulic　diameter　of　2　mm　and　a　volume　flowrate　of　30　mL/min,　60　mL/min,　90　mL/min,　120　mL/min　respectively.　The　study　focused　on　the　effect　of　inlet　vapor　quality　on　the　flow　pattern　and　heat　transfer　characteristics　of　flow　condensation　in　the　mini-channel.　The　results　indicate　that　the　flow　pattern　in　flow　condensation　process　can　be　classified　into　annular　flow,　transition　flow,　slug　flow　and　bubble　flow　in　sequence　along　the　flow　direction.　As　the　inlet　vapor　quality　(xin)　increases,　the　dominance　of　annular　flow　gradually　increases,　making　it　difficult　to　capture　the　bubble　flow　with　high　volume　flowrate　and　high　inlet　vapor　quality.　This　phenomenon　is　observed　under　experimental　conditions　when:　1)　xin　is　equal　to　or　greater　than　0.75　at　a　volume　flowrate　of　60　mL/min,　2)　xin　is　equal　to　or　greater　than　0.55　at　a　volume　flowrate　of　90　mL/min,　and　3)　xin　is　equal　to　or　greater　than　0.25　at　a　volume　flowrate　of　120　mL/min.　The　increase　in　inlet　vapor　quality　is　beneficial　to　the　improvement　of　condensation　heat　transfer　coefficient.　In　this　experiment,　it　was　observed　that　the　local　heat　transfer　coefficient　was　decreased　by　up　to　83.7　%　when　comparing　the　lowest　vapor　quality　to　the　highest　at　the　same　volume　flowrate,　emphasizing　the　significance　of　inlet　vapor　quality　in　the　flow　condensation　during　the　heat　transfer　process.　©　2023　Elsevier　Ltd