Large　flume　model　tests　were　conducted　to　investigate　the　effects　of　vegetation　on　water　infiltration　and　slope　deformation　under　wetting-drying　cycles.　In　total,　two　flume　model　tests　were　carried　out,　one　was　planted　with　Schefflera　heptaphylla,　and　the　other　bare　slope　severed　as　a　reference.　Plant　characteristics,　volumetric　water　content,　matric　suction,　and　surface　runoff　were　well　documented.　Simultaneously,　slope　deformation　during　rainfall　was　analyzed　by　Particle　Image　Velocimetry　(PIV)　technology.　The　experimental　results　showed　that　the　growth　rate　of　plant　height　increased　as　light　intensity　increased.　At　the　initial　stages,　suctions　in　the　shallow　soil　layers　(i.e.　50　mm)　of　the　vegetated　slope　were　smaller　than　that　of　the　bare　slope.　However,　the　suction　in　the　vegetated　slope　increased　as　light　intensity　increased,　particularly　in　the　shallow　layer　(i.e.　150　mm),　where　it　was　about　10　kPa　larger　than　that　of　the　bare　slope.　In　addition,　vegetation　improved　the　rainfall　infiltration　rate,　which　increased　with　the　number　of　wetting-drying　cycles.　Under　the　same　condition,　the　cumulative　rainfall　infiltration　rate　of　the　vegetated　slope　was　approximately　twice　that　of　the　bare　slope.　While,　the　horizontal　and　vertical　deformation　rates　of　the　vegetated　slope　were　lower　than　those　of　bare　slope,　respectively.　This　indicates　that　vegetation　effectively　mitigates　slope　deformation　during　extreme　rainfall　and　enhances　slope　stability.