A　general　method　based　on　capillary　electrophoresis　with　electrochemical　detection　(CE-ED)　was　developed　for　identification　and　determination　of　five　flavonoids　(kaempferol,　apigenin,　myricetin,　quercetin　and　luteolin)　in　plant　species.　Running　buffer,　pH　and　concentration,　separation　voltage,　injection　time　and　detection　potential　were　investigated　to　acquire　the　optimum　conditions.　The　working　electrode　was　a　500　mu　m　diameter　carbon　disc　electrode　positioned　opposite　the　outlet　of　capillary.　At　room　temperature,　the　five　flavonoids　could　be　well　separated　within　21　min　in　a　60　cm　length　capillary　at　a　separation　voltage　of　19.5　kV　with　50　mM　Na2B4O7-100　mM　NaH2PO4　(pH　8.50)　as　the　running　buffer.　The　relationship　between　peak　currents　and　analyte　concentrations　was　linear　over　about　two　orders　of　magnitude,　and　the　detection　limits　(S/N　=　3)　were　ranging　from　0.12　to　0.21　mu　g/ml　for　all　analytes.　The　optimized　CE-ED　method　was　employed　to　analyze　the　above　flavonoids　in　different　parts　of　Portulaca　oleracea　L.　(c)　2006　Elsevier　B.V.　All　rights　reserved.