This　paper　presents　a　simulative　and　experimental　investigation　of　the　thermal　and　hydraulic　fields　of　the　TiO2-water　nanofluids　with　various　concentrations　inside　a　fan-microchannel　heat　sink.　The　computational　method　of　simulation　was　a　two-phase　mixture　model.　The　nanofluids　flow　and　heat　transfer　facility　which　could　measure　flow　rate,　import　and　export　of　pressure　drop　and　temperature　and　the　temperature　of　heating　film　was　set　up　for　the　experiment.　Reynolds　number　of　coolant　in　the　microchannel　was　between　207~465　and　the　heat　flux　of　heating　film　was　kept　in　2×106　W/m2.　The　results　show　that　the　relationship　between　the　friction　factor　and　Re　of　nanofluids　is　similar　to　that　of　water　within　the　fan-microchannel　and　the　friction　factor　is　larger　than　that　of　water.　The　friction　factor　decreases　while　the　Re　increases.　The　heat　transfer　performance　of　nanofluids　is　better　than　that　of　water.　Furthermore,　the　heat　transfer　enhancement　of　nanofluids　increases　with　increasing　Re　and　the　concentration　of　nanoparticles.　©　2016,　Beijing　University　of　Technology.　All　right　reserved.