The　local　resistance　characteristic　of　the　micro　throat　may　be　an　important　factor　affecting　oil　recovery　ratio,　which　is　also　a　problem　of　both　percolation　mechanics　and　multiphase　microfluidics.　In　this　paper,　rectangular　microchannels　had　been　etched　on　the　silicon　slice　with　the　technic　of　microfluidics,　one　of　which　is　a　straight　channel　with　no　throat　and　the　other　three　with　one　throat　respectively.　The　three　throats　are　different　in　dynamic　diameter;　however,　the　four　channels　are　exactly　the　same　when　the　throats　are　ignored.　Experiments　had　been　conducted　to　investigate　the　local　pressure　drop　characteristics　of　water　single-phase　and　oil-in-water　two-phase　flow　throw　the　micro　throats.　The　results　indicate　that　the　local　pressure　drop　is　larger　when　the　dynamic　diameter　of　the　throat　is　smaller　at　the　same　flow　rate.　In　addition,　the　local　pressure　drop　of　the　micro　throat　is　the　quadratic　polynomial　function　of　flow　rate,　the　intercept　of　which　is　zero.　The　first　power　term　of　the　function　indicates　the　frictional　resistance　and　the　quadratic　one　indicates　the　inlet　and　outlet　effect.　Furthermore,　the　trend　of　the　prediction　model　and　the　experimental　data　is　the　same,　in　spite　of　deviation　of　their　values,　which　indicates　that　the　prediction　of　the　term　of　the　inlet　and　outlet　effect　is　comparatively　accurate　and　that　of　the　frictional　resistance　term　is　not　quite　accurate.　These　results　may　be　caused　by　some　micro　perimeters　such　as　surface　tension,　surface　wettability　and　so　on,　and　further　research　is　necessary.　©　2019,　Science　Press.　All　right　reserved.