This　paper　examines　seismo-ionospheric　anomalies　(SIAs)　observed　by　the　French　satellite　DEMETER　(Detection　of　Electra-Magnetic　Emissions　Transmitted　from　Earthquake　Regions)　during　the　12　May　2008　M8.0　Wenchuan　earthquake.　Both　daytime　and　nighttime　electron　density　(Ne),　electron　temperature　(Te),　ion　density　(Ni)　and　ion　temperature　(Ti)　are　investigated.　A　statistical　analysis　of　the　box-and-whisker　method　is　utilized　to　see　if　the　four　DEMETER　datasets　1-6　days　before　and　after　the　earthquake　are　significantly　different.　The　analysis　is　employed　to　investigate　the　epicenter　and　three　reference　areas　along　the　same　magnetic　latitude　discriminating　the　SlAs　from　global　effects.　Results　show　that　the　nighttime　Ne　and　Ni　(daytime　Ti)　over　the　epicenter　significantly　decrease　(increase)　1-6　days　before　the　earthquake.　The　intersections　of　the　global　distribution　of　the　significant　differences　(or　anomalous　changes)　in　the　nighttime　Ne,　the　nighttime　Ni,　and　the　daytime　Ti　1-6　days　before　and　after　the　earthquake　specifically　appear　over　the　epicenter,　which　strongly　suggests　that　DEMETER　observes　SIAs　of　the　2008　M8.0　Wenchuan　earthquake.　(c)　2015　Elsevier　Ltd.　All　rights　reserved.