Two-phase　evaporative　cooling　technology　has　been　widely　used　for　the　electronic　cooling.　In　this　paper,　dynamic　performance　of　an　integrated　pumping　and　compression　evaporative　electronic　cooling　system　was　experimentally　and　theoretically　investigated　during　the　system　mode　variation.　A　mathematical　model　was　developed　based　on　the　ANSYS　fluent　and　validated　using　experimental　data.　The　results　showed　a　sharp　increase　in　the　cooling　temperature　before　the　stable　cooling　condition　was　achieved　as　the　system　operating　mode　changed　to　meet　the　heat　load　variation.　The　model　was　then　used　to　investigate　the　influence　of　the　different　opening　and　closing　order　of　the　valves　on　the　flow　rate　distributions　when　the　cooling　system　was　switched　from　liquid-pumping　mode　to　vapor-compression　mode.　The　results　showed　that　the　valve　sequences　had　a　large　influence　on　the　flow　distributions　during　the　switching　process.　This　valve　sequence　substantially　influenced　the　cooling　peak　temperature　when　the　control　time　for　the　whole　switching　process　was　longer　than　16　s.　This　analysis　indicated　that　an　appropriate　valve　sequence　could　reduce　the　sharp　change　of　cooling　temperature　and　increase　the　cooling　performance　during　the　system　switching　process.　(C)　2017　Elsevier　Ltd.　All　rights　reserved.