Based　on　equivalent　continuum　media　model,　the　fractured　soil　located　on　the　slope　surface　can　be　regarded　as　dual-porosity　media,　including　the　crack　network　and　the　pores　of　soil　matrix,　and　the　degree　of　fissure　and　the　average　fissure　width　as　the　introducing　variables　were　taken.　According　to　the　capillary　theory　and　the　pore-size　distribution,　an　effective　method　was　summarized　which　can　evaluate　equivalent　bi-modal　unsaturated　soil　property　functions　for　fractured　soil.　Then　this　method　was　applied　to　analyze　an　engineering　practice　on　how　the　crack　network　affects　the　seepage　field　under　rainfall　infiltration　condition.　The　results　show　that　the　crack　network　provides　a　priority　channel　for　rainfall　infiltration,　and　the　perched　water　table　is　formed　within　the　slope　typically　1-2　m　deep.　©,　2015,　Academia　Sinica.　All　right　reserved.