The　anti-clogging　performance　of　emitters　with　labyrinth　channels　is　a　key　factor　affecting　their　long-term　service.　Considering　the　limitation　of　evaluation　on　emitter＇s　anti-clogging　performance　at　present.　a　new　method　using　passage　rate　of　particles　as　the　evaluation　index　was　proposed　based　on　stochastic　trajectory　model　in　a　Lagrangian　reference　frame.　Using　orthogonal　design,　the　passage　rates　of　particles　of　16　trapezoidal　labyrinth　channels　with　various　geometries　were　calculated.　where　4　dimensionless　parameters　were　taken　as　the　factors.　The　results　obtained　from　analysis　of　range　and　variance　showed　that　the　influence　degree　on　passage　rate　of　particles　ranks　as　follows:　alpha　＞　D/W　＞　S/H　＞　H/D.　A　mathematic　model　was　established　between　the　particle　passage　rate　and　4　key　parameters　according　to　the　multivariable　regression　method,　which　can　be　used　to　predict　and　compare　the　anti-clogging　performance　of　trapezoidal　labyrinth　channels　with　different　geometries.　(C)　2010　Elsevier　B.V.　All　rights　reserved.