In　order　to　analyze　unsaturated　seepage　characteristics　of　slope　under　rainfall　infiltration,　a　rainfall　simulation　system　and　real-time　monitoring　system　were　employed　for　conducting　model　tests　to　simulate　the　rainfall-induced　unsaturated　soil　slope　failure　process　in　this　study.　The　real-time　response　of　infiltration　rate　and　wetting　front　of　soil　slope　with　different　slope　angles,　different　compaction　degrees　and　different　locations　under　different　rainfall　conditions　were　recorded　and　analyzed.　Results　show　that　steep　slope　and　high　compaction　degree　soil　are　not　conducive　to　rainfall　infiltration,　while　gentle　slope　and　low　compaction　degree　soil　have　a　quick　change　of　infiltration　rate;　the　concept　of　test　wetting　front　is　proposed　due　to　the　real-time　law　of　actual　soil　suction　and　water　content　under　rainfall　conditions　are　not　synchronized,　and　the　water　content　(suction)　wetting　front　point　can　be　determined　by　a　linear　intersection　of　water　content　(suction)　real-time　curve　transition　zone　and　residual　water　content　(suction)　after　rainfall;　considering　water　content　and　soil　suction　have　the　only　corresponding　relationship　under　unidirectional　wetting　and　drying　path,　the　time　needed　for　wetting　front　formation　can　be　seen　as　the　absolute　value　of　time　differences　between　water　content　and　suction　wetting　front　point.　Based　on　the　Lumb　formula　of　wetting　front　depth,　the　nonlinear　correction　expression　is　proposed　subsequently　by　comparing　the　scatter　distribution　of　wetting　front　measured　and　semi-empirical　values.　©　2018,　Editorial　Department　of　Earth　Science.　All　right　reserved.