Based　on　previous　studies,　related　empirical　correlations　of　laminar　convective　heat　transfer　in　microchannel　heat　sinks　are　summed　up　firstly.　They　include　pressure　drop,　friction　factor,　Nusselt　number　and　different　thermal　resistances,　etc.　The　corresponding　experiment　and　simulation　are　validated　the　accuracy　of　presented　empirical　model.　Deionized　water　is　used　as　working　fluid.　The　results　show　that　pressure　drop　and　Nusselt　number　obtained　from　experiment　and　simulation　are　compared　with　those　from　empirical　correlations,　showing　good　agreement　within　10%.　Furthermore,　different　thermal　resistances,　temperature　rise　of　fluid　and　flow　distribution　in　microchannel　heat　sinks　are　also　investigated.　Convective　thermal　resistance　plays　an　important　role　in　the　heat　transfer　process.　The　portion　of　it　exceeds　50%,　thus　convective　thermal　resistance　should　be　reduced　to　enhance　heat　transfer.　Temperature　rise　of　fluid　caused　by　convective　heat　transfer　is　a　domain　factor.　It　will　decrease　with　the　increase　of　Reynolds　number.　Moreover,　uniform　flow　distribution　leads　to　uniform　temperature　field　at　the　bottom　of　microchannel　heat　sinks.　In　order　to　eliminate　the　entrance　effect,　the　length　of　entrance　region　should　be　long　enough　to　obtained　uniform　flow　distribution　in　parallel-channel　heat　sinks.　The　theoretical　guidance　of　convective　heat　transfer　is　provided　for　optimizing　design　in　microchannel　heat　sinks.　(C)　2017　Published　by　Elsevier　Inc.